ScxmlEditor: Remove unused variable

Change-Id: I32218cb3cc24232240b1f81e745e815017f6252b
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/scxmleditor/common/graphicsview.cpp

@@ -100,7 +100,7 @@ void GraphicsView::updateView()
 
 void GraphicsView::resizeEvent(QResizeEvent *event)
 {
-    QRect r(QPoint(0, 0), event->size());
+    Q_UNUSED(event)
 
     // Init layout item if necessary
     initLayoutItem();