[gnome-control-center] color: Fix a critical warning in the new GtkTreeIter code

[Richard Hughes <rhughes src gnome org>]

commit 8283232b4491384366bdc0b494bd09d06b9b8b24
Author: Richard Hughes <richard hughsie com>
Date:   Fri Oct 21 16:01:37 2011 +0100

    color: Fix a critical warning in the new GtkTreeIter code

 panels/color/cc-color-panel.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/panels/color/cc-color-panel.c b/panels/color/cc-color-panel.c
index 5788a7a..add595f 100644
--- a/panels/color/cc-color-panel.c
+++ b/panels/color/cc-color-panel.c
@@ -1703,7 +1703,8 @@ skip:
                           GCM_PREFS_COLUMN_RADIO_VISIBLE, TRUE,
                           GCM_PREFS_COLUMN_RADIO_ACTIVE, i==0,
                           -1);
-      gtk_tree_iter_free (iter_tmp_p);
+      if (iter_tmp_p != NULL)
+        gtk_tree_iter_free (iter_tmp_p);
       g_free (title_tmp);
       g_free (sort_tmp);
       g_string_free (date_tmp, TRUE);