[gtk] GdkEvent: Remove unused struct

[Timm Bäder <baedert src gnome org>]

commit 01e985a8305d06b44f4a0b927aef0f3b1f383b3a
Author: Timm Bäder <mail baedert org>
Date:   Thu Jan 17 16:29:40 2019 +0100

    GdkEvent: Remove unused struct

 gdk/gdkevents.c | 8 --------
 1 file changed, 8 deletions(-)
---
diff --git a/gdk/gdkevents.c b/gdk/gdkevents.c
index 300974f3ce..052eaca640 100644
--- a/gdk/gdkevents.c
+++ b/gdk/gdkevents.c
@@ -64,14 +64,6 @@
  * of related touch events.
  */
 
-typedef struct _GdkIOClosure GdkIOClosure;
-
-struct _GdkIOClosure
-{
-  GDestroyNotify notify;
-  gpointer data;
-};
-
 /* Private variable declarations
  */