iio: ti-ads1015: Remove shift variable ads1015_read_raw

By using scan_type.realbits when processing raw data,
we use scan_type.shit only once, thus we don't need to define a local
variable for it anymore.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20211104082413.3681212-12-gwendal@chromium.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ti-ads1015.c

@@ -464,9 +464,7 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
 
 	mutex_lock(&data->lock);
 	switch (mask) {
-	case IIO_CHAN_INFO_RAW: {
-		int shift = chan->scan_type.shift;
-
+	case IIO_CHAN_INFO_RAW:
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
 			break;
@@ -487,7 +485,8 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
 			goto release_direct;
 		}
 
-		*val = sign_extend32(*val >> shift, 15 - shift);
+		*val = sign_extend32(*val >> chan->scan_type.shift,
+				     chan->scan_type.realbits - 1);
 
 		ret = ads1015_set_power_state(data, false);
 		if (ret < 0)
@@ -497,7 +496,6 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
 release_direct:
 		iio_device_release_direct_mode(indio_dev);
 		break;
-	}
 	case IIO_CHAN_INFO_SCALE:
 		idx = data->channel_data[chan->address].pga;
 		*val = ads1015_fullscale_range[idx];