net/mlx4_en: Fix the return value of a failure in VLAN VID add/kill

BugLink: https://bugs.launchpad.net/bugs/1878232

commit 93c098af upstream.

Modify mlx4_en_vlan_rx_[add/kill]_vid to return error value in case of
failure.

Fixes: 8e586137 ('net: make vlan ndo_vlan_rx_[add/kill]_vid return error value')
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -433,14 +433,18 @@ static int mlx4_en_vlan_rx_add_vid(struct net_device *dev,
 	mutex_lock(&mdev->state_lock);
 	if (mdev->device_up && priv->port_up) {
 		err = mlx4_SET_VLAN_FLTR(mdev->dev, priv);
-		if (err)
+		if (err) {
 			en_err(priv, "Failed configuring VLAN filter\n");
+			goto out;
+		}
 	}
-	if (mlx4_register_vlan(mdev->dev, priv->port, vid, &idx))
-		en_dbg(HW, priv, "failed adding vlan %d\n", vid);
-	mutex_unlock(&mdev->state_lock);
+	err = mlx4_register_vlan(mdev->dev, priv->port, vid, &idx);
+	if (err)
+		en_dbg(HW, priv, "Failed adding vlan %d\n", vid);
 
-	return 0;
+out:
+	mutex_unlock(&mdev->state_lock);
+	return err;
 }
 
 static int mlx4_en_vlan_rx_kill_vid(struct net_device *dev,
@@ -448,7 +452,7 @@ static int mlx4_en_vlan_rx_kill_vid(struct net_device *dev,
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 	struct mlx4_en_dev *mdev = priv->mdev;
-	int err;
+	int err = 0;
 
 	en_dbg(HW, priv, "Killing VID:%d\n", vid);
 
@@ -465,7 +469,7 @@ static int mlx4_en_vlan_rx_kill_vid(struct net_device *dev,
 	}
 	mutex_unlock(&mdev->state_lock);
 
-	return 0;
+	return err;
 }
 
 static void mlx4_en_u64_to_mac(unsigned char dst_mac[ETH_ALEN + 2], u64 src_mac)