[TCP]: rcvbuf lock when tcp_moderate_rcvbuf enabled

The rcvbuf lock should probably be honored here.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a97ed54..e9a54ae 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -456,7 +456,8 @@
 
 		tp->rcvq_space.space = space;
 
-		if (sysctl_tcp_moderate_rcvbuf) {
+		if (sysctl_tcp_moderate_rcvbuf &&
+		    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
 			int new_clamp = space;
 
 			/* Receive space grows, normalize in order to