[gtk+] Fix return value error in gtk_font_chooser_get_font_map

[Matthias Clasen <matthiasc src gnome org>]

commit a1e418ebd527a227722c0a8e1191241fe35bfdcf
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Tue May 12 10:23:59 2015 +0800

    Fix return value error in gtk_font_chooser_get_font_map
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749248

 gtk/gtkfontchooser.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkfontchooser.c b/gtk/gtkfontchooser.c
index bd99dee..d295ce0 100644
--- a/gtk/gtkfontchooser.c
+++ b/gtk/gtkfontchooser.c
@@ -485,7 +485,7 @@ gtk_font_chooser_get_font_map (GtkFontChooser *fontchooser)
 {
   PangoFontMap *fontmap;
 
-  g_return_if_fail (GTK_IS_FONT_CHOOSER (fontchooser));
+  g_return_val_if_fail (GTK_IS_FONT_CHOOSER (fontchooser), NULL);
 
   g_object_get (fontchooser, "font-map", &fontmap, NULL);