[media] cx231xx: fix double lock typo

This was supposed to be an unlock on the error path.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Devin Heitmueller <dheitmueller@hauppauge.com>
Cc: Palash Bandyopadhyay < palash.bandyopadhyay@conexant.com>
Cc: Sri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx231xx/cx231xx-i2c.c

@@ -372,7 +372,7 @@ static int cx231xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 			rc = cx231xx_i2c_check_for_device(i2c_adap, &msgs[i]);
 			if (rc < 0) {
 				dprintk2(2, " no device\n");
-				mutex_lock(&dev->i2c_lock);
+				mutex_unlock(&dev->i2c_lock);
 				return rc;
 			}