tcp: convert icsk_user_timeout from jiffies to msecs

This is a preparatory commit. Part of this series that improves the
socket TCP_USER_TIMEOUT option accuracy. Implement Eric Dumazets idea
to convert icsk->icsk_user_timeout from jiffies to msecs. To eliminate
the msecs_to_jiffies() and jiffies_to_msecs() dance in future.

Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index bce53b1..514aaac 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2989,7 +2989,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 		if (val < 0)
 			err = -EINVAL;
 		else
-			icsk->icsk_user_timeout = msecs_to_jiffies(val);
+			icsk->icsk_user_timeout = val;
 		break;
 
 	case TCP_FASTOPEN:
@@ -3445,7 +3445,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		break;
 
 	case TCP_USER_TIMEOUT:
-		val = jiffies_to_msecs(icsk->icsk_user_timeout);
+		val = icsk->icsk_user_timeout;
 		break;
 
 	case TCP_FASTOPEN: