OMAP: DSS2: DSI: Print an error message if DSI clock calc fails

Print an error message if dsi_calc_clock_rates() fails just like it's
done when dispc_calc_clock_rates() fails.

Signed-off-by: Ville Syrjälä <ville.syrjala@nokia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index 72b859c..04d84d1 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -2967,8 +2967,10 @@
 	cinfo.regm3 = dssdev->phy.dsi.div.regm3;
 	cinfo.regm4 = dssdev->phy.dsi.div.regm4;
 	r = dsi_calc_clock_rates(&cinfo);
-	if (r)
+	if (r) {
+		DSSERR("Failed to calc dsi clocks\n");
 		return r;
+	}
 
 	r = dsi_pll_set_clock_div(&cinfo);
 	if (r) {