hwmon: (tmp421) Fix return value

Propagate return value obtained from i2c_smbus_read_byte_data()
instead of hardcoding.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Andre Prendel <andre.prendel@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index 964c1d6..ae26b06 100644
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -210,7 +210,7 @@
 	if (config < 0) {
 		dev_err(&client->dev,
 			"Could not read configuration register (%d)\n", config);
-		return -ENODEV;
+		return config;
 	}
 
 	config_orig = config;