IB/hns: Fix the bug with modifying the MAC address without removing the driver

When modified the MAC address used hns_roce_mac function, we release and create
reserved qp again, It is not necessary to use spin_lock_bh and spin_unlock_bh in
handle_en_event, Otherwise, it will occur a error. This patch mainly fixes it.
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hns/hns_roce_main.c

@@ -125,8 +125,6 @@ static int handle_en_event(struct hns_roce_dev *hr_dev, u8 port,
 		return -ENODEV;
 	}
 
-	spin_lock_bh(&hr_dev->iboe.lock);
-
 	switch (event) {
 	case NETDEV_UP:
 	case NETDEV_CHANGE:
@@ -144,7 +142,6 @@ static int handle_en_event(struct hns_roce_dev *hr_dev, u8 port,
 		break;
 	}
 
-	spin_unlock_bh(&hr_dev->iboe.lock);
 	return 0;
 }