services: Accept <inferior-package>s in lieu of <package>s.

* gnu/services/authentication.scm (fprintd-configuration)
(nslcd-configuration): Substitute file-like objects for package ones.
* gnu/services/cgit.scm (cgit-configuration, opaque-cgit-configuration):
Likewise.
* gnu/services/cups.scm (package-list?, cups-configuration): Likewise.
* gnu/services/dns.scm (verify-knot-configuration)
(ddclient-configuration): Likewise.
* gnu/services/docker.scm (docker-configuration): Likewise.
* gnu/services/file-sharing.scm (transmission-daemon-configuration): Likewise.
* gnu/services/getmail.scm (getmail-configuration): Likewise.
* gnu/services/mail.scm (dovecot-configuration)
(opaque-dovecot-configuration): Likewise.
* gnu/services/messaging.scm (prosody-configuration)
(opaque-prosody-configuration): Likewise.
* gnu/services/monitoring.scm (zabbix-server-configuration)
(zabbix-agent-configuration): Likewise.
* gnu/services/networking.scm (opendht-configuration): Likewise.
* gnu/services/pm.scm (tlp-configuration): Likewise.
* gnu/services/telephony.scm (jami-configuration): Likewise.
* gnu/services/virtualization.scm (libvirt-configuration)
(qemu-guest-agent-configuration): Likewise.
* gnu/services/vpn.scm (openvpn-client-configuration): Likewise.

1 files changed, 2 insertions, 2 deletions

diff --git a/gnu/services/cups.scm b/gnu/services/cups.scm
index 1b8e19bed8..d965014cd8 100644
--- a/gnu/services/cups.scm
+++ b/gnu/services/cups.scm
@@ -482,13 +482,13 @@ programs.")
     (serialize-space-separated-string-list field-name vars)))
 
 (define (package-list? val)
-  (and (list? val) (and-map package? val)))
+  (and (list? val) (and-map file-like? val)))
 (define (serialize-package-list field-name val)
   #f)
 
 (define-configuration cups-configuration
   (cups
-   (package cups)
+   (file-like cups)
    "The CUPS package.")
   (extensions
    (package-list (list brlaser cups-filters epson-inkjet-printer-escpr