bonding: fix locking in bond_loadbalance_arp_mon()

The commit 1d3ee88ae0d605629bf369
(bonding: add netlink attributes to slave link dev)
has add rtmsg_ifinfo() in bond_set_active_slave() and
bond_set_backup_slave(), so the two function need to
called in RTNL lock, but bond_loadbalance_arp_mon()
only calling these functions in RCU, warning message
will occurs.

fix this by add a new function bond_slave_state_change(),
which will reset the slave's state after slave link check,
so remove the bond_set_xxx_slave() from the cycle and only
record the slave_state_changed, this will call the new
function to set all slaves to new state in RTNL later.

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 1a9062f..86ccfb9 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -303,6 +303,19 @@
 	}
 }
 
+static inline void bond_slave_state_change(struct bonding *bond)
+{
+	struct list_head *iter;
+	struct slave *tmp;
+
+	bond_for_each_slave(bond, tmp, iter) {
+		if (tmp->link == BOND_LINK_UP)
+			bond_set_active_slave(tmp);
+		else if (tmp->link == BOND_LINK_DOWN)
+			bond_set_backup_slave(tmp);
+	}
+}
+
 static inline int bond_slave_state(struct slave *slave)
 {
 	return slave->backup;