bonding: delete unused arp_mon_pt

Now all received packets are handled by bond_handle_frame,
and arp_mon_pt isn't used any more.

Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bonding.h

@@ -240,7 +240,6 @@ struct bonding {
 	struct   bond_params params;
 	struct   list_head vlan_list;
 	struct   vlan_group *vlgrp;
-	struct   packet_type arp_mon_pt;
 	struct   workqueue_struct *wq;
 	struct   delayed_work mii_work;
 	struct   delayed_work arp_work;