iio: adc: ad7606: using claim_direct_scoped for code simplification

Using iio_device_claim_direct_scoped instead of calling `iio_device
_claim_direct_modeand later callingiio_device_release_direct_mode`

This should make code cleaner and error handling easier
Co-authored-by: Lais Nuto <laisnuto@usp.br>
Signed-off-by: Lais Nuto <laisnuto@usp.br>
Signed-off-by: Jorge Harrisonn <jorge.harrisonn@usp.br>
Link: https://lore.kernel.org/r/20240501215724.26655-2-jorge.harrisonn@usp.brSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7606.c

@@ -174,17 +174,14 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
 
 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
-		ret = iio_device_claim_direct_mode(indio_dev);
-		if (ret)
-			return ret;
-
+		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
 			ret = ad7606_scan_direct(indio_dev, chan->address);
-		iio_device_release_direct_mode(indio_dev);
-
 			if (ret < 0)
 				return ret;
-		*val = (short)ret;
+			*val = (short) ret;
 			return IIO_VAL_INT;
+		}
+		unreachable();
 	case IIO_CHAN_INFO_SCALE:
 		if (st->sw_mode_en)
 			ch = chan->address;