net/hns3: skip VF register access when PF in FLR

net/hns3: skip VF register access when PF in FLR

According to the protocol of PCIe, FLR to a PF device resets the PF state
as well as the SR-IOV extended capability including VF Enable which means
that VFs no longer exist.

When PF device is in FLR reset stage, at this time, the register state
of VF device is not reliable, so VF device's register state detection
is not carried out in PF FLR.

In this case, we just ignore the register states to avoid accessing
nonexistent register and return false in the internal function named
hns3vf_is_reset_pending to indicate that there are no other reset states
that need to be processed by PMD driver.

Fixes: 2790c6464725 ("net/hns3: support device reset")
Cc: stable@dpdk.org
Signed-off-by: Hongbo Zheng <zhenghongbo3@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>