bonding: enable netpoll without checking link status

Only slaves that are up should transmit netpoll frames, so there is no
need to check to see if a slave is up before enabling netpoll on it.
This resolves a reported failure on active-backup bonds where a slave
interface is down when netpoll was enabled.
Signed-off-by: NAndy Gospodarek <andy@greyhouse.net>
Tested-by: NWANG Cong <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -1347,8 +1347,6 @@ static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 
 	read_lock(&bond->lock);
 	bond_for_each_slave(bond, slave, i) {
-		if (!IS_UP(slave->dev))
-			continue;
 		err = slave_enable_netpoll(slave);
 		if (err) {
 			__bond_netpoll_cleanup(bond);