net: Fix duplicate volatile warning.

jiffies is defined as "volatile".

  extern unsigned long volatile __jiffy_data jiffies;

ACCESS_ONCE() uses "volatile".
As a result, some compilers warn duplicate `volatile' for ACCESS_ONCE(jiffies).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 55590ab..6beb1ff 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -303,7 +303,7 @@
 
 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 {
-	unsigned long now = ACCESS_ONCE(jiffies);
+	unsigned long now = jiffies;
 	
 	if (neigh->used != now)
 		neigh->used = now;