regulator: change message level on probing lp872x driver

Use err log rather than warning message when the platform data is NULL

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/lp872x.c b/drivers/regulator/lp872x.c
index e8f54ef..471f8e8 100644
--- a/drivers/regulator/lp872x.c
+++ b/drivers/regulator/lp872x.c
@@ -885,7 +885,7 @@
 	};
 
 	if (!pdata) {
-		dev_warn(&cl->dev, "no platform data\n");
+		dev_err(&cl->dev, "no platform data\n");
 		return -EINVAL;
 	}