expression result unused [-Werror,-Wunused-value]

Change-Id: I57b44c1997ac286fcb4caf8e3027e3b5996fc377

canvas/source/cairo/cairo_canvashelper.cxx

@@ -1513,7 +1513,7 @@ namespace cairocanvas
     geometry::IntegerSize2D CanvasHelper::getSize()
     {
         if( !mpSurfaceProvider )
-            geometry::IntegerSize2D(1, 1); // we're disposed
+            return geometry::IntegerSize2D(1, 1); // we're disposed
 
         return ::basegfx::unotools::integerSize2DFromB2ISize( maSize );
     }