vxlan: unregister on namespace exit

Fix memory leaks and other badness from VXLAN network namespace
teardown. When network namespace is removed, all the vxlan devices should
be unregistered (not closed).

Signed-off-by: Stephen Hemminger <[e-mail]>
Reviewed-by: Pravin B Shelar <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/vxlan.c

···
 {
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
 	struct vxlan_dev *vxlan;
+	LIST_HEAD(list);
 
 	rtnl_lock();
 	list_for_each_entry(vxlan, &vn->vxlan_list, next)
-		dev_close(vxlan->dev);
+		unregister_netdevice_queue(vxlan->dev, &list);
+	unregister_netdevice_many(&list);
 	rtnl_unlock();
 }