Revert "gnu: Fix Krita."

This reverts commit 5f63905096e456097fca206f56ce9257f72faf64.

This commit caused `guix pull` to crash like this:

------
Backtrace:
In ice-9/boot-9.scm:
   222:29 19 (map1 _)
   222:29 18 (map1 _)
   222:29 17 (map1 _)
   222:29 16 (map1 _)
   222:17 15 (map1 (((gnu packages kde)) ((gnu packages libevent)) ((gnu packages libidn)) ((gnu packages #)) ((?)) ?))
  3297:17 14 (resolve-interface (gnu packages kde) #:select _ #:hide _ #:prefix _ #:renamer _ #:version _)
In ice-9/threads.scm:
    390:8 13 (_ _)
In ice-9/boot-9.scm:
  3223:13 12 (_)
In ice-9/threads.scm:
    390:8 11 (_ _)
In ice-9/boot-9.scm:
  3507:20 10 (_)
   2806:4  9 (save-module-excursion _)
  3527:26  8 (_)
In unknown file:
           7 (primitive-load-path "gnu/packages/kde" #<procedure 7f68d6fe5da0 at ice-9/boot-9.scm:3514:37 ()>)
In ice-9/eval.scm:
   626:19  6 (_ #<directory (gnu packages kde) 7f68d6175b40>)
   293:34  5 (_ #<directory (gnu packages kde) 7f68d6175b40>)
   173:47  4 (_ #(#<directory (gnu packages kde) 7f68d6175b40> #<promise #<procedure 7f68dc5a5d00 at ice-9/eval.sc?>))
    159:9  3 (_ #(#<directory (gnu packages kde) 7f68d6175b40> #<promise #<procedure 7f68dc5a5d00 at ice-9/eval.sc?>))
   191:35  2 (_ #(#<directory (gnu packages kde) 7f68d6175b40> #<promise #<procedure 7f68dc5a5d00 at ice-9/eval.sc?>))
   223:20  1 (proc #(#<directory (gnu packages kde) 7f68d6175b40> #<promise #<procedure 7f68dc5a5d00 at ice-9/eval?>))
In unknown file:
           0 (%resolve-variable (7 . qtbase) #<directory (gnu packages kde) 7f68d6175b40>)

ERROR: In procedure %resolve-variable:
error: qtbase: unbound variable
------

3 files changed, 1 insertions, 120 deletions

diff --git a/gnu/packages/kde.scm b/gnu/packages/kde.scm
index 9fa8ed7c15..9a80e362b6 100644
--- a/gnu/packages/kde.scm
+++ b/gnu/packages/kde.scm
@@ -360,14 +360,6 @@ a module for implementing ODF Gantt charts, which are bar charts that
 illustrate project schedules.")
     (license license:gpl2+)))
 
-(define qtbase-for-krita
-  (package
-    (inherit qtbase)
-    (source (origin
-              (inherit (package-source qtbase))
-              (patches (append (origin-patches (package-source qtbase))
-                               (search-patches "qtbase-fix-krita-deadlock.patch")))))))
-
 (define-public krita
   (package
     (name "krita")
@@ -442,7 +434,7 @@ illustrate project schedules.")
        ("openexr" ,openexr)
        ("perl" ,perl)
        ("poppler-qt5" ,poppler-qt5)
-       ("qtbase" ,qtbase-for-krita)
+       ("qtbase" ,qtbase)
        ("qtdeclarative" ,qtdeclarative)
        ("qtmultimedia" ,qtmultimedia)
        ("qtsvg" ,qtsvg)
diff --git a/gnu/packages/patches/qtbase-fix-krita-deadlock.patch b/gnu/packages/patches/qtbase-fix-krita-deadlock.patch
deleted file mode 100644
index d3554be3c9..0000000000
--- a/gnu/packages/patches/qtbase-fix-krita-deadlock.patch
+++ /dev/null
@@ -1,110 +0,0 @@
-Fix a deadlock in Krita:
-
-https://bugreports.qt.io/browse/QTBUG-83207
-
-Patch copied from Qt bug tracker:
-
-https://codereview.qt-project.org/c/qt/qtbase/+/296034
-
-From 276fa8383a7535765be7182883ef4aade17ce013 Mon Sep 17 00:00:00 2001
-From: Thiago Macieira <thiago.macieira@intel.com>
-Date: Thu, 02 Apr 2020 12:08:41 -0300
-Subject: [PATCH] QLibrary: fix deadlock caused by fix to QTBUG-39642
-
-Commit ae6f73e8566fa76470937aca737141183929a5ec inserted a mutex around
-the entire load_sys(). We had reasoed that deadlocks would only occur if
-the object creation in instance() recursed into its own instance(),
-which was already a bug. But we had forgotten that dlopen()/
-LoadLibrary() executes initialization code from the module being loaded,
-which could cause a recursion back into the same QPluginLoader or
-QLibrary object. This recursion is benign because the module *is* loaded
-and dlopen()/LoadLibrary() returns the same handle.
-
-[ChangeLog][QtCore][QLibrary and QPluginLoader] Fixed a deadlock that
-would happen if the plugin or library being loaded has load-time
-initialization code (C++ global variables) that recursed back into the
-same QLibrary or QPluginLoader object.
-
-PS: QLibraryPrivate::loadPlugin() updates pluginState outside a mutex
-lock, so pluginState should be made an atomic variable. Once that is
-done, we'll only need locking the mutex to update errorString (no
-locking before loading).
-
-Fixes: QTBUG-83207
-Task-number: QTBUG-39642
-Change-Id: Ibdc95e9af7bd456a94ecfffd160209304e5ab2eb
-Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
-Reviewed-by: David Faure <david.faure@kdab.com>
----
-
-diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
-index ddb053c..be9d92b 100644
---- a/src/corelib/plugin/qlibrary.cpp
-+++ b/src/corelib/plugin/qlibrary.cpp
-@@ -576,9 +576,7 @@
- 
-     Q_TRACE(QLibraryPrivate_load_entry, fileName);
- 
--    mutex.lock();
-     bool ret = load_sys();
--    mutex.unlock();
-     if (qt_debug_component()) {
-         if (ret) {
-             qDebug() << "loaded library" << fileName;
-diff --git a/src/corelib/plugin/qlibrary_unix.cpp b/src/corelib/plugin/qlibrary_unix.cpp
-index 017aa97..a5c72f8 100644
---- a/src/corelib/plugin/qlibrary_unix.cpp
-+++ b/src/corelib/plugin/qlibrary_unix.cpp
-@@ -123,6 +123,7 @@
- 
- bool QLibraryPrivate::load_sys()
- {
-+    QMutexLocker locker(&mutex);
-     QString attempt;
-     QFileSystemEntry fsEntry(fileName);
- 
-@@ -213,6 +214,7 @@
-     }
- #endif
- 
-+    locker.unlock();
-     bool retry = true;
-     Handle hnd = nullptr;
-     for (int prefix = 0; retry && !hnd && prefix < prefixes.size(); prefix++) {
-@@ -273,6 +275,8 @@
-         }
-     }
- #endif
-+
-+    locker.relock();
-     if (!hnd) {
-         errorString = QLibrary::tr("Cannot load library %1: %2").arg(fileName, qdlerror());
-     }
-diff --git a/src/corelib/plugin/qlibrary_win.cpp b/src/corelib/plugin/qlibrary_win.cpp
-index 000bf76..ef58724 100644
---- a/src/corelib/plugin/qlibrary_win.cpp
-+++ b/src/corelib/plugin/qlibrary_win.cpp
-@@ -78,6 +78,7 @@
-     //     fileName
-     //
-     // NB If it's a plugin we do not ever try the ".dll" extension
-+    QMutexLocker locker(&mutex);
-     QStringList attempts;
- 
-     if (pluginState != IsAPlugin)
-@@ -95,6 +96,7 @@
-         attempts.prepend(QDir::rootPath() + fileName);
- #endif
- 
-+    locker.unlock();
-     Handle hnd = nullptr;
-     for (const QString &attempt : qAsConst(attempts)) {
- #ifndef Q_OS_WINRT
-@@ -115,6 +117,7 @@
- #ifndef Q_OS_WINRT
-     SetErrorMode(oldmode);
- #endif
-+    locker.relock();
-     if (!hnd) {
-         errorString = QLibrary::tr("Cannot load library %1: %2").arg(
-                     QDir::toNativeSeparators(fileName), qt_error_string());
diff --git a/gnu/packages/qt.scm b/gnu/packages/qt.scm
index e0e71c595d..0cb36427a0 100644
--- a/gnu/packages/qt.scm
+++ b/gnu/packages/qt.scm
@@ -342,7 +342,6 @@ developers using C++ or QML, a CSS & JavaScript like language.")
 (define-public qtbase
   (package
     (name "qtbase")
-    ;; TODO Remove ((gnu packages kde) qtbase-for-krita) when upgrading qtbase.
     (version "5.14.2")
     (source (origin
              (method url-fetch)