net/hns3: fix max packet size rollback in PF

net/hns3: fix max packet size rollback in PF

HNS3 PF driver use the hns->pf.mps to restore the MTU when a reset
occurs.
If user fails to configure the MTU, the MPS of PF may not be restored to
the original value.

Fixes: 25fb790f7868 ("net/hns3: fix HW buffer size on MTU update")
Fixes: 1f5ca0b460cd ("net/hns3: support some device operations")
Fixes: d51867db65c1 ("net/hns3: add initialization")
Cc: stable@dpdk.org
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>