Staging: batman-adv: Create batman_if only on register event

We try to get all events for all net_devices to be able to add special
sysfs folders for the batman-adv configuration. This also includes such
events like NETDEV_POST_INIT which has no valid kobject according to
v2.6.32-rc3-13-g7ffbe3fd. This would create an oops in that situation.

It is enough to create the batman_if only on NETDEV_REGISTER events
because we will also receive those events for devices which already
existed when we registered the notifier call.
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/batman-adv/hard-interface.c

@@ -393,15 +393,13 @@ static int hard_if_event(struct notifier_block *this,
 	/* FIXME: each batman_if will be attached to a softif */
 	struct bat_priv *bat_priv = netdev_priv(soft_device);
 
-	if (!batman_if)
-		batman_if = hardif_add_interface(net_dev);
+	if (!batman_if && event == NETDEV_REGISTER)
+			batman_if = hardif_add_interface(net_dev);
 
 	if (!batman_if)
 		goto out;
 
 	switch (event) {
-	case NETDEV_REGISTER:
-		break;
 	case NETDEV_UP:
 		hardif_activate_interface(soft_device, bat_priv, batman_if);
 		break;