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>
diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c
index 147614e..70ac599 100644
--- a/drivers/net/wan/dlci.c
+++ b/drivers/net/wan/dlci.c
@@ -477,7 +477,7 @@
 static int dlci_dev_event(struct notifier_block *unused,
 			  unsigned long event, void *ptr)
 {
-	struct net_device *dev = (struct net_device *) ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
 	if (dev_net(dev) != &init_net)
 		return NOTIFY_DONE;