tcp: mark tcp_congestion_ops read_mostly

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
index 00ca688d..813b43a 100644
--- a/net/ipv4/tcp_illinois.c
+++ b/net/ipv4/tcp_illinois.c
@@ -322,7 +322,7 @@
 	}
 }
 
-static struct tcp_congestion_ops tcp_illinois = {
+static struct tcp_congestion_ops tcp_illinois __read_mostly = {
 	.flags		= TCP_CONG_RTT_STAMP,
 	.init		= tcp_illinois_init,
 	.ssthresh	= tcp_illinois_ssthresh,