tcp: remove obsolete validity concern

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 957c4e3..6f2a3f4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2087,10 +2087,6 @@
 	if (!tcp_can_forward_retransmit(sk))
 		return;
 
-	/* If nothing is SACKed, highest_sack in the loop won't be valid */
-	if (!tp->sacked_out)
-		return;
-
 	if (tp->forward_skb_hint)
 		skb = tp->forward_skb_hint;
 	else