[gtk] Remove an unused struct

[Matthias Clasen <matthiasc src gnome org>]

commit 979a7e8afa6ec799ccb11b6bf0d92a64c552aa45
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 27 11:56:21 2018 -0400

    Remove an unused struct
    
    Positive side-effect: visual c no longer has an empty struct
    to complain about.

 gtk/inspector/inspectoroverlay.c | 6 ------
 1 file changed, 6 deletions(-)
---
diff --git a/gtk/inspector/inspectoroverlay.c b/gtk/inspector/inspectoroverlay.c
index a95c9bc814..303c61f7d8 100644
--- a/gtk/inspector/inspectoroverlay.c
+++ b/gtk/inspector/inspectoroverlay.c
@@ -23,12 +23,6 @@
 
 #include "gtkintl.h"
 
-typedef struct _GtkInspectorOverlayPrivate GtkInspectorOverlayPrivate;
-
-struct _GtkInspectorOverlayPrivate
-{
-};
-
 G_DEFINE_ABSTRACT_TYPE (GtkInspectorOverlay, gtk_inspector_overlay, G_TYPE_OBJECT)
 
 static void