tcp: No need to clear retransmit_skb_hint when SACKing

Because lost counter no longer requires tuning, this is
trivial to remove (the tuning wouldn't have been too
hard either) because no "new" retransmittable skb appeared
below retransmit_skb_hint when SACKing for sure.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 28e93f1..d017aed 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1298,9 +1298,6 @@
 					~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
 				tp->lost_out -= tcp_skb_pcount(skb);
 				tp->retrans_out -= tcp_skb_pcount(skb);
-
-				/* clear lost hint */
-				tp->retransmit_skb_hint = NULL;
 			}
 		} else {
 			if (!(sacked & TCPCB_RETRANS)) {
@@ -1319,9 +1316,6 @@
 			if (sacked & TCPCB_LOST) {
 				TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
 				tp->lost_out -= tcp_skb_pcount(skb);
-
-				/* clear lost hint */
-				tp->retransmit_skb_hint = NULL;
 			}
 		}
 
@@ -1351,7 +1345,6 @@
 	if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) {
 		TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
 		tp->retrans_out -= tcp_skb_pcount(skb);
-		tp->retransmit_skb_hint = NULL;
 	}
 
 	return flag;