Network Drop Monitor: Fix skb_kill_datagram

Commit ead2ceb ("Network Drop Monitor:
Adding kfree_skb_clean for non-drops and modifying end-of-line points
for skbs") established new conventions for identifying dropped packets.

Align skb_kill_datagram() with these conventions so that packets that
get dropped just before the copy to userspace are properly tracked.

Signed-off-by: John Dykstra <john.dykstra1@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/datagram.c

@@ -260,7 +260,9 @@ int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags)
 		spin_unlock_bh(&sk->sk_receive_queue.lock);
 	}
 
-	skb_free_datagram(sk, skb);
+	kfree_skb(skb);
+	sk_mem_reclaim_partial(sk);
+
 	return err;
 }