net: hns3: fix tx timeout issue

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7OS1B


CVE: NA

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Currently, the driver knocks the ring doorbell before updating
the ring->last_to_use in tx flow. if the hardware transmiting
packet and napi poll scheduling are fast enough, it may get
the old ring->last_to_use in drivers' napi poll.
In this case, the driver will think the tx is not completed, and
return directly without clear the flag __QUEUE_STATE_STACK_XOFF,
which may cause tx timeout.

Fixes: 62ef41eb ("net: hns3: optimize the tx clean process")
Signed-off-by: Jian Shen <shenjian15@huawei.com>