neigh: reorder fields in struct neighbour

On 64bit arches, there are two 32bit holes that we can remove.

sizeof(struct neighbour) shrinks from 0xf8 to 0xf0 bytes
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/neighbour.h

@@ -102,11 +102,11 @@ struct neighbour {
 	__u8			nud_state;
 	__u8			type;
 	__u8			dead;
+	atomic_t		refcnt;
 	atomic_t		probes;
 	rwlock_t		lock;
 	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
 	struct hh_cache		*hh;
-	atomic_t		refcnt;
 	int			(*output)(struct sk_buff *skb);
 	struct sk_buff_head	arp_queue;
 	struct timer_list	timer;