tunnels: fix netns vs proto registration ordering

Same stuff as in ip_gre patch: receive hook can be called before netns
setup is done, oopsing in net_generic().

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
static void prl_list_destroy_rcu(struct rcu_head *head)
{
	struct ip_tunnel_prl_entry *p, *n;

	p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
	do {
		n = p->next;
		kfree(p);
		p = n;
	} while (p);
}

static void prl_list_destroy_rcu(struct rcu_head *head)
{
	struct ip_tunnel_prl_entry *p, *n;

	p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
	do {
		n = p->next;
		kfree(p);
		p = n;
	} while (p);
}
