netdevice: Add a function to check macvlan port

Similar to a check for macvlan device, netif_is_macvlan(), add
another function to check if a device is used as macvlan port.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed