iio: adc: max1027: unlock on error path in max1027_read_single_value()

If max1027_wait_eoc() fails then call iio_device_release_direct_mode()
before returning.

Fixes: a0e83165 ("iio: adc: max1027: Introduce an end of conversion helper")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YsbztVuAXnau2cIZ@kiliSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/max1027.c

@@ -349,8 +349,7 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
 	if (ret < 0) {
 		dev_err(&indio_dev->dev,
 			"Failed to configure conversion register\n");
-		iio_device_release_direct_mode(indio_dev);
-		return ret;
+		goto release;
 	}
 
 	/*
@@ -360,11 +359,12 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
 	 */
 	ret = max1027_wait_eoc(indio_dev);
 	if (ret)
-		return ret;
+		goto release;
 
 	/* Read result */
 	ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
 
+release:
 	iio_device_release_direct_mode(indio_dev);
 
 	if (ret < 0)