IB/hns: Simplify function of pd alloc and qp alloc

Hns_roce_pd_alloc and hns_roce_reserve_range_qp use unnecessary
transformation of parameters. This patch simplify these two
functions.

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Dongdong Huang(Donald) <hdd.huang@huawei.com>
Reviewed-by: Wei Hu <xavier.huwei@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>