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/caif/caif_usb.c b/net/caif/caif_usb.c
index 942e00a..75ed04b 100644
--- a/net/caif/caif_usb.c
+++ b/net/caif/caif_usb.c
@@ -121,9 +121,9 @@
 };
 
 static int cfusbl_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);
 	struct caif_dev_common common;
 	struct cflayer *layer, *link_support;
 	struct usbnet *usbnet;