[mutter] window: Fix some minor constant type issues

[Jasper St. Pierre <jstpierre src gnome org>]

commit 7fa15c74b4f79487554ce596b06299ba4b97cf4d
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Wed Aug 13 18:14:15 2014 -0400

    window: Fix some minor constant type issues

 src/core/window.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index 988354c..1dbd120 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -7574,7 +7574,7 @@ void
 meta_window_set_transient_for (MetaWindow *window,
                                MetaWindow *parent)
 {
-  if (meta_window_appears_focused (window) && window->transient_for != None)
+  if (meta_window_appears_focused (window) && window->transient_for != NULL)
     meta_window_propagate_focus_appearance (window, FALSE);
 
   /* may now be a dialog */
@@ -7619,7 +7619,7 @@ meta_window_set_transient_for (MetaWindow *window,
   if (!window->constructing && !window->override_redirect)
     meta_window_queue (window, META_QUEUE_MOVE_RESIZE);
 
-  if (meta_window_appears_focused (window) && window->transient_for != None)
+  if (meta_window_appears_focused (window) && window->transient_for != NULL)
     meta_window_propagate_focus_appearance (window, TRUE);
 }