[gtk] tooltipwindow: Cosmetic fix

[Matthias Clasen <matthiasc src gnome org>]

commit 68b3b66c03804b15b8ed80970abfa7f3b3bff0d6
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Dec 29 22:47:49 2019 -0500

    tooltipwindow: Cosmetic fix

 gtk/gtktooltipwindow.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtktooltipwindow.c b/gtk/gtktooltipwindow.c
index d4615647c7..28e63d095f 100644
--- a/gtk/gtktooltipwindow.c
+++ b/gtk/gtktooltipwindow.c
@@ -44,7 +44,7 @@
 
 struct _GtkTooltipWindow
 {
-  GtkWindow parent_type;
+  GtkWindow parent_instance;
 
   GdkSurface *surface;
   GskRenderer *renderer;