OMAP: DSS2: OMAPFB: Skip unnecessary set_overlay_info()

In omapfb_enable_overlay() if the overlay state is already what we want
skip the set_overlay_info().
Signed-off-by: NVille Syrjälä <ville.syrjala@nokia.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

drivers/video/omap2/omapfb/omapfb.h

@@ -148,6 +148,8 @@ static inline int omapfb_overlay_enable(struct omap_overlay *ovl,
 	struct omap_overlay_info info;
 
 	ovl->get_overlay_info(ovl, &info);
+	if (info.enabled == enable)
+		return 0;
 	info.enabled = enable;
 	return ovl->set_overlay_info(ovl, &info);
 }