RDMA/hns: Fix xarray race in hns_roce_create_qp_common()

RDMA/hns: Fix xarray race in hns_roce_create_qp_common()

Similar to the SRQ case the hr_qp is stored in the xarray before it is
fully initialized. Unlike the SRQ case the error unwinds do not wait for
the completion so keep the refcount 0 until the function succeeds.

Fixes: 9a4435375cd1 ("IB/hns: Add driver files for hns RoCE driver")
Link: https://patch.msgid.link/r/14-v1-41f3135e5565+9d2-rdma_ai_fixes1_jgg@nvidia.com
Suggested-by: Junxian Huang <huangjunxian6@hisilicon.com>
Reviewed-by: Junxian Huang <huangjunxian6@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>