[INET]: Use list_head-s in inetpeer.c

The inetpeer.c tracks the LRU list of inet_perr-s, but makes
it by hands. Use the list_head-s for this.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index aa10a81..ad8404b 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -22,7 +22,7 @@
 	__be32			v4daddr;	/* peer's address */
 	__u16			avl_height;
 	__u16			ip_id_count;	/* IP ID for the next packet */
-	struct inet_peer	*unused_next, **unused_prevp;
+	struct list_head	unused;
 	__u32			dtime;		/* the time of last use of not
 						 * referenced entries */
 	atomic_t		refcnt;