RDMA/hns: Only assign dest_qp if IB_QP_DEST_QPN bit is set

Only when the IB_QP_DEST_QPN flag of attr_mask is set is it valid to
assign the dest_qp_num into the dest_qp field of qp context.
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hns/hns_roce_hw_v1.c

@@ -2888,6 +2888,7 @@ static int hns_roce_v1_m_qp(struct ib_qp *ibqp, const struct ib_qp_attr *attr,
 			       QP_CONTEXT_QPC_BYTES_32_RESPONDER_RESOURCES_S,
 			       ilog2((unsigned int)attr->max_dest_rd_atomic));
 
+		if (attr_mask & IB_QP_DEST_QPN)
 			roce_set_field(context->qpc_bytes_36,
 				       QP_CONTEXT_QPC_BYTES_36_DEST_QP_M,
 				       QP_CONTEXT_QPC_BYTES_36_DEST_QP_S,