batman-adv: Remove explicit casts cast from void* for store

It is not necessary to cast a void* to the pointer type when we just
store it and don't want to do pointer arithmetic before the actual
assignment.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 915e12b..e626e75 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -523,7 +523,7 @@
 static int hard_if_event(struct notifier_block *this,
 			 unsigned long event, void *ptr)
 {
-	struct net_device *net_dev = (struct net_device *)ptr;
+	struct net_device *net_dev = ptr;
 	struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
 	struct hard_iface *primary_if = NULL;
 	struct bat_priv *bat_priv;