[media] si2157: simplify si2157_cmd_execute() error path

Remove if () from firmware command error path as there should not be
any error prone conditional logic there. Use goto labels instead.
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/tuners/si2157.c

@@ -65,15 +65,11 @@ static int si2157_cmd_execute(struct si2157_dev *dev, struct si2157_cmd *cmd)
 		}
 	}
 
-	ret = 0;
+	mutex_unlock(&dev->i2c_mutex);
+	return 0;
 
 err_mutex_unlock:
 	mutex_unlock(&dev->i2c_mutex);
-	if (ret)
-		goto err;
-
-	return 0;
-err:
 	dev_dbg(&dev->client->dev, "failed=%d\n", ret);
 	return ret;
 }