IB/hns: Fix bug of memory leakage for registering user mr

While the page size attribute of umem is illegal, we should release
umem that get by ib_umem_get interface.

Also, we should return a non-zero value while pbl number is wrong.

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