xfrm: Move device notifications to a sepatate file

This is needed for the upcomming IPsec device offloading.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 236cbbc..7befca2 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2929,21 +2929,6 @@
 }
 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
 
-static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
-{
-	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-
-	switch (event) {
-	case NETDEV_DOWN:
-		xfrm_garbage_collect(dev_net(dev));
-	}
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block xfrm_dev_notifier = {
-	.notifier_call	= xfrm_dev_event,
-};
-
 #ifdef CONFIG_XFRM_STATISTICS
 static int __net_init xfrm_statistics_init(struct net *net)
 {
@@ -3020,7 +3005,7 @@
 	INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
 	INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
 	if (net_eq(net, &init_net))
-		register_netdevice_notifier(&xfrm_dev_notifier);
+		xfrm_dev_init();
 	return 0;
 
 out_bydst: