[gnome-desktop] Fix gcc warning

[Benjamin Otte <otte src gnome org>]

commit f307d00ddb7507346dbbf5fc76b0e73daeaa2df4
Author: Benjamin Otte <otte redhat com>
Date:   Tue Nov 30 22:36:20 2010 +0100

    Fix gcc warning

 libgnome-desktop/gnome-desktop-thumbnail.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/libgnome-desktop/gnome-desktop-thumbnail.c b/libgnome-desktop/gnome-desktop-thumbnail.c
index 71871df..ad15bf0 100644
--- a/libgnome-desktop/gnome-desktop-thumbnail.c
+++ b/libgnome-desktop/gnome-desktop-thumbnail.c
@@ -619,7 +619,9 @@ mimetype_supported_by_gdk_pixbuf (const char *mime_type)
         if (!formats_hash) {
                 GSList *formats, *list;
 
-                formats_hash = g_hash_table_new_full (g_str_hash, g_content_type_equals, g_free, NULL);
+                formats_hash = g_hash_table_new_full (g_str_hash,
+                                                      (GEqualFunc) g_content_type_equals,
+                                                      g_free, NULL);
 
                 formats = gdk_pixbuf_get_formats ();
                 list = formats;