[TCP]: remove unused argument to cong_avoid op

None of the existing TCP congestion controls use the rtt value pased
in the ca_ops->cong_avoid interface.  Which is lucky because seq_rtt
could have been -1 when handling a duplicate ack.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 4624501..be27a33 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -15,7 +15,7 @@
 #define TCP_SCALABLE_AI_CNT	50U
 #define TCP_SCALABLE_MD_SCALE	3
 
-static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
+static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack,
 				    u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);