ip: Make use of the inline function dst_metric_locked()

Signed-off-by: Satoru SATOH <satoru.satoh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index 6d7bcd5..3b40bc2 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -210,7 +210,7 @@
 {
 	return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
 		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
-		 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
+		 !(dst_metric_locked(dst, RTAX_MTU))));
 }
 
 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);