batman-adv: Place kref_get for bla_backbone_gw 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/bridge_loop_avoidance.c

@@ -526,11 +526,9 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig,
 	atomic_set(&entry->wait_periods, 0);
 	ether_addr_copy(entry->orig, orig);
 	INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report);
-
-	/* one for the hash, one for returning */
 	kref_init(&entry->refcount);
-	kref_get(&entry->refcount);
 
+	kref_get(&entry->refcount);
 	hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
 				     batadv_compare_backbone_gw,
 				     batadv_choose_backbone_gw, entry,