[mutter] MetaPluginManager: Don't return void value

[Jonas Ådahl <jadahl src gnome org>]

commit 79f90c147cca4f9040ff745f8cfefa7c1b75d64c
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Thu Feb 21 09:24:03 2019 +0100

    MetaPluginManager: Don't return void value
    
    The spec for `meta_plugin_manager_confirm_display_change()` is to return
    `void`, no need to return a value there.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/456

 src/compositor/meta-plugin-manager.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/compositor/meta-plugin-manager.c b/src/compositor/meta-plugin-manager.c
index 236b6b1d3..ab2d8128f 100644
--- a/src/compositor/meta-plugin-manager.c
+++ b/src/compositor/meta-plugin-manager.c
@@ -299,9 +299,9 @@ meta_plugin_manager_confirm_display_change (MetaPluginManager *plugin_mgr)
   MetaPluginClass *klass = META_PLUGIN_GET_CLASS (plugin);
 
   if (klass->confirm_display_change)
-    return klass->confirm_display_change (plugin);
+    klass->confirm_display_change (plugin);
   else
-    return meta_plugin_complete_display_change (plugin, TRUE);
+    meta_plugin_complete_display_change (plugin, TRUE);
 }
 
 gboolean