[NET]: use hlist_unhashed()

Use hlist_unhashed() rather than accessing inside data structure.

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 1da294c..e837f98 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -150,7 +150,7 @@
 
 static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
 {
-	return tw->tw_death_node.pprev != NULL;
+	return !hlist_unhashed(&tw->tw_death_node);
 }
 
 static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)