Bug 1739339 - Address nit correctly.

MANUAL PUSH: Bustage fix CLOSED TREE

widget/gtk/nsDragService.cpp

@@ -1959,8 +1959,7 @@ void nsDragService::SetDragIcon(GdkDragContext* aContext) {
           // When mDragPopup has a parent it's already attached to D&D context.
           // That may happens when D&D operation is aborted but not finished
           // on Gtk side yet so let's remove it now.
-          GtkWidget* parent;
-          if (parent = gtk_widget_get_parent(gtkWidget)) {
+          if (GtkWidget* parent = gtk_widget_get_parent(gtkWidget)) {
             gtk_container_remove(GTK_CONTAINER(parent), gtkWidget);
           }
           LOGDRAGSERVICE(("  set drag popup [%p]", widget.get()));