[TCP]: Fix off by one in tcp_fragment() "already sent" test.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 6094db5..15e1134 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -499,7 +499,7 @@
 	/* If this packet has been sent out already, we must
 	 * adjust the various packet counters.
 	 */
-	if (after(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) {
+	if (!before(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) {
 		int diff = old_factor - tcp_skb_pcount(skb) -
 			tcp_skb_pcount(buff);