iio: dac: max5821: Make use of the helper function dev_err_probe()

When possible use dev_err_probe help to properly deal with the
PROBE_DEFER error, the benefit is that DEFER issue will be logged
in the devices_deferred debugfs file.
Using dev_err_probe() can reduce code size, and the error value
gets printed.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20210928013902.1341-5-caihuoqing@baidu.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/max5821.c

@@ -321,12 +321,9 @@ static int max5821_probe(struct i2c_client *client,
 	}
 
 	data->vref_reg = devm_regulator_get(&client->dev, "vref");
-	if (IS_ERR(data->vref_reg)) {
-		ret = PTR_ERR(data->vref_reg);
-		dev_err(&client->dev,
-			"Failed to get vref regulator: %d\n", ret);
-		return ret;
-	}
+	if (IS_ERR(data->vref_reg))
+		return dev_err_probe(&client->dev, PTR_ERR(data->vref_reg),
+				     "Failed to get vref regulator\n");
 
 	ret = regulator_enable(data->vref_reg);
 	if (ret) {