driver: macvlan: Remove the rcu member of macvlan_port

When free macvlan_port in macvlan_port_destroy, it is safe to free
directly because netdev_rx_handler_unregister could enforce one
grace period.
So it is unnecessary to use kfree_rcu for macvlan_port.

Signed-off-by: Gao Feng <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/macvlan.c

···
 	struct net_device	*dev;
 	struct hlist_head	vlan_hash[MACVLAN_HASH_SIZE];
 	struct list_head	vlans;
-	struct rcu_head		rcu;
 	struct sk_buff_head	bc_queue;
 	struct work_struct	bc_work;
 	bool 			passthru;
···
 	cancel_work_sync(&port->bc_work);
 	__skb_queue_purge(&port->bc_queue);
 
-	kfree_rcu(port, rcu);
+	kfree(port);
 }
 
 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])