[gtk+] Fix compile warning.

[Carlos Garnacho <carlosg src gnome org>]

commit 814957021f5223b99ceb4b23a953c0eb09f30dcc
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jun 13 17:33:47 2010 +0200

    Fix compile warning.

 gtk/gtkstylecontext.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkstylecontext.c b/gtk/gtkstylecontext.c
index 848d809..d760f7b 100644
--- a/gtk/gtkstylecontext.c
+++ b/gtk/gtkstylecontext.c
@@ -498,7 +498,7 @@ gtk_style_context_list_child_classes (GtkStyleContext *context)
       link = link->next;
 
       child_class = g_quark_to_string (link_class->class_quark);
-      classes = g_list_prepend (classes, child_class);
+      classes = g_list_prepend (classes, (gchar *) child_class);
     }
 
   return classes;