RDMA/hns: Fix incorrect vlan enable bit in QPC

The QPC_RQ/SQ_VLAN_EN bit in QPC should be enabled, not the QPC mask.

Fixes: f0cb411a

 ("RDMA/hns: Use new interface to modify QP context")
Link: https://lore.kernel.org/r/1624438201-11915-1-git-send-email-liweihang@huawei.com
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>