iio: adc: max1118: 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/20211008092858.495-4-caihuoqing@baidu.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/max1118.c

@@ -221,10 +221,9 @@ static int max1118_probe(struct spi_device *spi)
 
 	if (id->driver_data == max1118) {
 		adc->reg = devm_regulator_get(&spi->dev, "vref");
-		if (IS_ERR(adc->reg)) {
-			dev_err(&spi->dev, "failed to get vref regulator\n");
-			return PTR_ERR(adc->reg);
-		}
+		if (IS_ERR(adc->reg))
+			return dev_err_probe(&spi->dev, PTR_ERR(adc->reg),
+					     "failed to get vref regulator\n");
 		ret = regulator_enable(adc->reg);
 		if (ret)
 			return ret;