net: pass info struct via netdevice notifier

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan.c

@@ -341,7 +341,7 @@ static void __vlan_device_event(struct net_device *dev, unsigned long event)
 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			     void *ptr)
 {
-	struct net_device *dev = ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct vlan_group *grp;
 	struct vlan_info *vlan_info;
 	int i, flgs;