batman-adv: free skb on TVLV parsing success

When the TVLV parsing routine succeed the skb is left
untouched thus leading to a memory leak.

Fix this by consuming the skb in case of success.

Introduced by ef261577
("batman-adv: tvlv - basic infrastructure")
Reported-by: Russel Senior <russell@personaltelco.net>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Tested-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

net/batman-adv/routing.c

@@ -918,6 +918,8 @@ int batadv_recv_unicast_tvlv(struct sk_buff *skb,
 
 	if (ret != NET_RX_SUCCESS)
 		ret = batadv_route_unicast_packet(skb, recv_if);
+	else
+		consume_skb(skb);
 
 	return ret;
 }