videoaggregator: Don't try to return void

warning C4098: 'gst_video_aggregator_parallel_convert_pad_finalize':
'void' function returning a value

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1155>

gst-libs/gst/video/gstvideoaggregator.c

@@ -900,8 +900,7 @@ gst_video_aggregator_parallel_convert_pad_finalize (GObject * object)
     }
   }
 
-  return
-      G_OBJECT_CLASS
+  G_OBJECT_CLASS
       (gst_video_aggregator_parallel_convert_pad_parent_class)->finalize
       (object);
 }