[gtk+/wip/matthiasc/help-overlay] Fix a compiler warning

[Matthias Clasen <matthiasc src gnome org>]

commit 27ed7508ce3d30729211739aad944472caa4eebf
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Oct 21 06:51:25 2015 -0400

    Fix a compiler warning

 gtk/gtkapplicationwindow.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkapplicationwindow.c b/gtk/gtkapplicationwindow.c
index 9b7bbb7..919d92c 100644
--- a/gtk/gtkapplicationwindow.c
+++ b/gtk/gtkapplicationwindow.c
@@ -1004,7 +1004,7 @@ gtk_application_window_set_help_overlay (GtkApplicationWindow *window,
   g_signal_connect (help_overlay, "delete-event",
                     G_CALLBACK (gtk_widget_hide_on_delete), NULL);
 
-  if (!g_action_map_lookup_action (window->priv->actions, "show-help-overlay"))
+  if (!g_action_map_lookup_action (G_ACTION_MAP (window->priv->actions), "show-help-overlay"))
     {
       GSimpleAction *action;