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/include/net/tcp.h b/include/net/tcp.h
index c9a75db..0aeb2eb 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -928,7 +928,7 @@
 /* Use define here intentionally to get WARN_ON location shown at the caller */
 #define tcp_verify_left_out(tp)	WARN_ON(tcp_left_out(tp) > tp->packets_out)
 
-void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
+void tcp_enter_cwr(struct sock *sk);
 __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst);
 
 /* The maximum number of MSS of available cwnd for which TSO defers