batman-adv: Place kref_get for tvlv_container 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/tvlv.c

@@ -257,8 +257,13 @@ void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
 	spin_lock_bh(&bat_priv->tvlv.container_list_lock);
 	tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
 	batadv_tvlv_container_remove(bat_priv, tvlv_old);
+
+	kref_get(&tvlv_new->refcount);
 	hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
 	spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
+
+	/* don't return reference to new tvlv_container */
+	batadv_tvlv_container_put(tvlv_new);
 }
 
 /**