iio: adc: ad7124 fix indentation issue, remove extra tab

A return statement is indented one level too deeply; clean this
up by removing a tab.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7124.c

@@ -411,7 +411,7 @@ static int ad7124_init_channel_vref(struct ad7124_state *st,
 			dev_err(&st->sd.spi->dev,
 				"Error, trying to use external voltage reference without a %s regulator.\n",
 				ad7124_ref_names[refsel]);
-				return PTR_ERR(st->vref[refsel]);
+			return PTR_ERR(st->vref[refsel]);
 		}
 		st->channel_config[channel_number].vref_mv =
 			regulator_get_voltage(st->vref[refsel]);