RDMA/hns: Bugfix pbl configuration for rereg mr

Current hns driver assigned the first two PBL page addresses from previous
registered MR to the hardware when reregister MR changing the memory
locations occurred. This will lead to PBL addressing error as the PBL has
already been released. This patch fixes this wrong assignment by using the
page address from new allocated PBL.

Fixes: a2c80b7b ("RDMA/hns: Add rereg mr support for hip08")
Signed-off-by: Yixian Liu <liuyixian@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>