gtp: remove duplicate code in gtp_dellink()

gtp_encap_disable() in gtp_dellink() is unnecessary because it will be
called by unregister_netdevice().
unregister_netdevice() internally calls gtp_dev_uninit() by ->ndo_uninit().
And gtp_dev_uninit() calls gtp_encap_disable().

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/gtp.c

@@ -694,7 +694,6 @@ static void gtp_dellink(struct net_device *dev, struct list_head *head)
 {
 	struct gtp_dev *gtp = netdev_priv(dev);
 
-	gtp_encap_disable(gtp);
 	gtp_hashtable_free(gtp);
 	list_del_rcu(&gtp->list);
 	unregister_netdevice_queue(dev, head);