hwmon: (ds1621) fix coccinelle warnings

drivers/hwmon/ds1621.c:381:1-3: WARNING: PTR_RET can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: coccinelle/api/ptr_ret.cocci

CC: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

drivers/hwmon/ds1621.c

@@ -378,10 +378,7 @@ static int ds1621_probe(struct i2c_client *client,
 	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
 							   client->name, data,
 							   ds1621_groups);
-	if (IS_ERR(hwmon_dev))
-		return PTR_ERR(hwmon_dev);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
 static const struct i2c_device_id ds1621_id[] = {