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/mac80211/iface.c b/net/mac80211/iface.c
index 60f1ce5..d2c3fd1 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1717,10 +1717,9 @@
 }
 
 static int netdev_notify(struct notifier_block *nb,
-			 unsigned long state,
-			 void *ndev)
+			 unsigned long state, void *ptr)
 {
-	struct net_device *dev = ndev;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct ieee80211_sub_if_data *sdata;
 
 	if (state != NETDEV_CHANGENAME)