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/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index 45a7df6..56a6146 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -292,9 +292,9 @@
 
 /* notify Phonet of device events */
 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
-				void *arg)
+				void *ptr)
 {
-	struct net_device *dev = arg;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
 	switch (what) {
 	case NETDEV_REGISTER: