[PATCH] iio/adc/nau7802: Improve unlocking of a mutex in nau7802_read_raw()

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Tue, 13 Mar 2018 20:52:26 +0100

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only once in this function implementation.

* Replace two calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/iio/adc/nau7802.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/nau7802.c b/drivers/iio/adc/nau7802.c
index 8997e74a8847..68d06a492760 100644
--- a/drivers/iio/adc/nau7802.c
+++ b/drivers/iio/adc/nau7802.c
@@ -303,10 +303,8 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
                 *   - Channel 2 is value 1 in the CHS register
                 */
                ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL2);
-               if (ret < 0) {
-                       mutex_unlock(&st->lock);
-                       return ret;
-               }
+               if (ret < 0)
+                       goto unlock;
 
                if (((ret & NAU7802_CTRL2_CHS_BIT) && !chan->channel) ||
                                (!(ret & NAU7802_CTRL2_CHS_BIT) &&
@@ -316,18 +314,15 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
                                        NAU7802_REG_CTRL2,
                                        NAU7802_CTRL2_CHS(chan->channel) |
                                        NAU7802_CTRL2_CRS(st->sample_rate));
-
-                       if (ret < 0) {
-                               mutex_unlock(&st->lock);
-                               return ret;
-                       }
+                       if (ret < 0)
+                               goto unlock;
                }
 
                if (st->client->irq)
                        ret = nau7802_read_irq(indio_dev, chan, val);
                else
                        ret = nau7802_read_poll(indio_dev, chan, val);
-
+unlock:
                mutex_unlock(&st->lock);
                return ret;
 
-- 
2.16.2