RDMA/hns: Fix QP state judgement before sending work requests

The QP can accept send work requests only when the QP is
in the states that allow them to be submitted.

This patch updates the QP state judgement based on the
specification.

Signed-off-by: Yixian Liu <liuyixian@huawei.com>
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>