media: dvb-usb-v2: af9035: fix missing unlock

Instead of returning an error, goto the mutex unlock at
the end of the function.

Fixes smatch warning:

drivers/media/usb/dvb-usb-v2/af9035.c:467 af9035_i2c_master_xfer() warn: inconsistent returns '&d->i2c_mutex'.
  Locked on  : 326,387
  Unlocked on: 465,467

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: 7bf744f ("media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer")
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Author: Hans Verkuil

drivers/media/usb/dvb-usb-v2/af9035.c

@@ -322,8 +322,10 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
 			ret = -EOPNOTSUPP;
 		} else if ((msg[0].addr == state->af9033_i2c_addr[0]) ||
 			   (msg[0].addr == state->af9033_i2c_addr[1])) {
-			if (msg[0].len < 3 || msg[1].len < 1)
-				return -EOPNOTSUPP;
+			if (msg[0].len < 3 || msg[1].len < 1) {
+				ret = -EOPNOTSUPP;
+				goto unlock;
+			}
 			/* demod access via firmware interface */
 			u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 |
 					msg[0].buf[2];
@@ -383,8 +385,10 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
 			ret = -EOPNOTSUPP;
 		} else if ((msg[0].addr == state->af9033_i2c_addr[0]) ||
 			   (msg[0].addr == state->af9033_i2c_addr[1])) {
-			if (msg[0].len < 3)
-				return -EOPNOTSUPP;
+			if (msg[0].len < 3) {
+				ret = -EOPNOTSUPP;
+				goto unlock;
+			}
 			/* demod access via firmware interface */
 			u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 |
 					msg[0].buf[2];
@@ -459,6 +463,7 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap,
 		ret = -EOPNOTSUPP;
 	}
 
+unlock:
 	mutex_unlock(&d->i2c_mutex);
 
 	if (ret < 0)