[TCP]: Fix linkage errors on i386.

To avoid raw division, use ktime_to_timeval() to get usec.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
index b4e062a..43294ad 100644
--- a/net/ipv4/tcp_lp.c
+++ b/net/ipv4/tcp_lp.c
@@ -266,7 +266,7 @@
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct lp *lp = inet_csk_ca(sk);
 
-	tcp_lp_rtt_sample(sk,  ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC);
+	tcp_lp_rtt_sample(sk,  ktime_to_us(net_timedelta(last)));
 
 	/* calc inference */
 	if (tcp_time_stamp > tp->rx_opt.rcv_tsecr)