Fix surface offset when using borders

sway/tree/container.c

@@ -423,8 +423,8 @@ struct sway_container *container_at(struct sway_container *parent,
 					soutput->sway_output->wlr_output);
 			double ox = lx - output_box->x;
 			double oy = ly - output_box->y;
-			double view_sx = ox - swayc->x;
-			double view_sy = oy - swayc->y;
+			double view_sx = ox - sview->x;
+			double view_sy = oy - sview->y;
 
 			double _sx, _sy;
 			struct wlr_surface *_surface;