Bluetooth: 6lowpan: Do not free skb when packet is dropped

If we need to drop the message because of some error in the
compression etc, then do not free the skb as that is done
automatically in other part of networking stack.
Signed-off-by: NJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/6lowpan.c

@@ -390,7 +390,6 @@ static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 
 drop:
 	dev->stats.rx_dropped++;
-	kfree_skb(skb);
 	return NET_RX_DROP;
 }