video: rockchip: dw_mipi_dsi: Return 0 from dsi_phy_init on success

ret is undefined if external phy is not used resulting in bogus
error being returned in that scenario.

Signed-off-by: Ondrej Jirman <megi@xff.cz>
diff --git a/drivers/video/rockchip/dw_mipi_dsi_rockchip.c b/drivers/video/rockchip/dw_mipi_dsi_rockchip.c
index b7d6b51..5e8db6b 100644
--- a/drivers/video/rockchip/dw_mipi_dsi_rockchip.c
+++ b/drivers/video/rockchip/dw_mipi_dsi_rockchip.c
@@ -460,7 +460,7 @@
 	dw_mipi_dsi_phy_write(dsi, HS_TX_DATA_LANE_EXIT_STATE_TIME_CONTROL,
 			      BIT(5) | ns2bc(dsi, 100));
 
-	return ret;
+	return 0;
 }
 
 static void dsi_phy_post_set_mode(void *priv_data, unsigned long mode_flags)