batman-adv: Place kref_get for nc_node near use

It is hard to understand why the refcnt is increased when it isn't done
near the actual place the new reference is used. So using kref_get right
before the place which requires the reference and in the same function
helps to avoid accidental problems caused by incorrect reference counting.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net/batman-adv/network-coding.c

@@ -859,7 +859,6 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 	/* Initialize nc_node */
 	INIT_LIST_HEAD(&nc_node->list);
 	kref_init(&nc_node->refcount);
-	kref_get(&nc_node->refcount);
 	ether_addr_copy(nc_node->addr, orig_node->orig);
 	kref_get(&orig_neigh_node->refcount);
 	nc_node->orig_node = orig_neigh_node;
@@ -878,6 +877,7 @@ batadv_nc_get_nc_node(struct batadv_priv *bat_priv,
 
 	/* Add nc_node to orig_node */
 	spin_lock_bh(lock);
+	kref_get(&nc_node->refcount);
 	list_add_tail_rcu(&nc_node->list, list);
 	spin_unlock_bh(lock);