tcp: Remove unnecessary arg from tcp_enter_cwr and tcp_init_cwnd_reduction

Since Yuchung's 9b44190dc11 (tcp: refactor F-RTO), tcp_enter_cwr is always
called with set_ssthresh = 1. Thus, we can remove this argument from
tcp_enter_cwr. Further, as we remove this one, tcp_init_cwnd_reduction
is then always called with set_ssthresh = true, and so we can get rid of
this argument as well.

Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index bcee13c..306dd5d 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -979,7 +979,7 @@
 	if (likely(err <= 0))
 		return err;
 
-	tcp_enter_cwr(sk, 1);
+	tcp_enter_cwr(sk);
 
 	return net_xmit_eval(err);
 }