[mutter] surface-actor-x11: Fix "incompatible pointer type" error

[Rico Tzschichholz <ricotz src gnome org>]

commit ecc254c659d670df0f24ec5202d895b90b4ad4fb
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Fri Aug 22 07:38:08 2014 +0200

    surface-actor-x11: Fix "incompatible pointer type" error
    
    Caused by e73c46ce033eb3b63c77a90eb2dabd9a2e7e3444

 src/compositor/meta-surface-actor-x11.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/meta-surface-actor-x11.c b/src/compositor/meta-surface-actor-x11.c
index c8b3762..3563f96 100644
--- a/src/compositor/meta-surface-actor-x11.c
+++ b/src/compositor/meta-surface-actor-x11.c
@@ -205,7 +205,7 @@ meta_surface_actor_x11_process_damage (MetaSurfaceActor *actor,
         priv->does_full_damage = TRUE;
     }
 
-  if (!is_visible (actor))
+  if (!is_visible (self))
     return;
 
   cogl_texture_pixmap_x11_update_area (priv->texture, x, y, width, height);