vrf: ndo_add|del_slave drop unnecessary checks

When ndo_add|del_slave ops are used, they're taken from the respective
master device's netdev ops, so if the master device is a VRF only then
the VRF ops will get called thus no need to check the type of the
master.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vrf.c

@@ -393,8 +393,7 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 
 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 {
-	if (!netif_is_vrf(dev) || netif_is_vrf(port_dev) ||
-	    vrf_is_slave(port_dev))
+	if (netif_is_vrf(port_dev) || vrf_is_slave(port_dev))
 		return -EINVAL;
 
 	return do_vrf_add_slave(dev, port_dev);
@@ -431,9 +430,6 @@ static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 
 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 {
-	if (!netif_is_vrf(dev))
-		return -EINVAL;
-
 	return do_vrf_del_slave(dev, port_dev);
 }