[gtk+] switch: Fix build

[Timm Bäder <baedert src gnome org>]

commit 239f14cc96a7bf43b7e60e2b83cba437261a7fbc
Author: Timm Bäder <mail baedert org>
Date:   Mon Jan 16 21:01:59 2017 +0100

    switch: Fix build
    
    Partial revert of 2b6b5c1c8fecdd66172516812ed3f1825619dafc, which
    removed a little too much.

 gtk/gtkswitch.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkswitch.c b/gtk/gtkswitch.c
index ede2fc4..cc2e1ff 100644
--- a/gtk/gtkswitch.c
+++ b/gtk/gtkswitch.c
@@ -191,7 +191,9 @@ gtk_switch_multipress_gesture_pressed (GtkGestureMultiPress *gesture,
                                        GtkSwitch            *sw)
 {
   GtkSwitchPrivate *priv = sw->priv;
+  GtkAllocation allocation;
 
+  gtk_widget_get_allocation (GTK_WIDGET (sw), &allocation);
   gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
 
   /* If the press didn't happen in the draggable handle,