net: hns3: fix for not calculating TX BD send size correctly

With GRO and fraglist support, the SKB can be aggregated to
a total size of 65535, and when that SKB is forwarded through
a bridge, the size of the SKB may be pushed to exceed the size
of 65535 when br_dev_queue_push_xmit() is called.

The max send size of BD supported by the HW is 65535, when a SKB
with a headlen of over 65535 is sent to the driver, the driver
needs to use multi BD to send the linear data, and the send size
of the last BD is calculated incorrectly by the driver who is
using '&' operation, which causes a TX error.

Use '%' operation to fix this problem.

Fixes: 3fe13ed9 ("net: hns3: avoid mult + div op in critical data path")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>