[mutter] build: Fix return value in meta-background.c

[Ting-Wei Lan <lantw src gnome org>]

commit 0aa4c4d43e356d706bb4517bbb5c2626c29f0234
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Fri Sep 4 11:44:34 2015 +0800

    build: Fix return value in meta-background.c
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754545

 src/compositor/meta-background.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/meta-background.c b/src/compositor/meta-background.c
index b869077..a6b9caa 100644
--- a/src/compositor/meta-background.c
+++ b/src/compositor/meta-background.c
@@ -527,7 +527,7 @@ draw_texture (MetaBackground        *self,
       bare_region_visible = TRUE;
       break;
     default:
-      g_return_if_reached();
+      g_return_val_if_reached(FALSE);
     }
 
   return bare_region_visible;