[media] si2168: simplify si2168_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: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index e00bc04..3c102e5 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -66,15 +66,11 @@
 		}
 	}
 
-	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(&client->dev, "failed=%d\n", ret);
 	return ret;
 }