OMAP: DSS2: Fix error path in omap_dsi_update()

In the case of an error on calling dsi_update_screen_l4(), a
successful framedone callback is still sent to panel-taal. An
error should be returned to taal_update() instead.
Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

drivers/video/omap2/dss/dsi.c

@@ -2920,7 +2920,12 @@ int omap_dsi_update(struct omap_dss_device *dssdev,
 
 		dsi_update_screen_dispc(dssdev, x, y, w, h);
 	} else {
-		dsi_update_screen_l4(dssdev, x, y, w, h);
+		int r;
+
+		r = dsi_update_screen_l4(dssdev, x, y, w, h);
+		if (r)
+			return r;
+
 		dsi_perf_show("L4");
 		callback(0, data);
 	}