[mutter] background-group: Fix cast warning

[Jasper St. Pierre <jstpierre src gnome org>]

commit 7116d9cedb938cc04dc40255935fd4ad5bdc3277
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Thu Nov 21 15:14:40 2013 -0500

    background-group: Fix cast warning

 src/compositor/meta-background-group.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/meta-background-group.c b/src/compositor/meta-background-group.c
index 3d680de..092dd18 100644
--- a/src/compositor/meta-background-group.c
+++ b/src/compositor/meta-background-group.c
@@ -46,7 +46,7 @@ meta_background_group_set_clip_region (MetaBackgroundGroup *self,
                                        cairo_region_t      *region)
 {
   ClutterActor *child;
-  for (child = clutter_actor_get_first_child (self);
+  for (child = clutter_actor_get_first_child (CLUTTER_ACTOR (self));
        child != NULL;
        child = clutter_actor_get_next_sibling (child))
     {