modules/xbps: fix error message (#4438)

The previous error message was not giving the full or even correct
information to the user.

(cherry picked from commit d3adde4)

changelogs/fragments/4438-fix-error-message.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - xbps - fix error message that is reported when installing packages fails (https://github.com/ansible-collections/community.general/pull/4438).

plugins/modules/packaging/os/xbps.py

@@ -230,7 +230,9 @@ def install_packages(module, xbps_path, state, packages):
         module.params['upgrade_xbps'] = False
         install_packages(module, xbps_path, state, packages)
     elif rc != 0 and not (state == 'latest' and rc == 17):
-        module.fail_json(msg="failed to install %s" % (package))
+        module.fail_json(msg="failed to install %s packages(s)"
+                         % (len(toInstall)),
+                         packages=toInstall)
 
     module.exit_json(changed=True, msg="installed %s package(s)"
                      % (len(toInstall)),