RDMA/irdma: Remove the unused spin lock in struct irdma_qp_uk

The spin lock in struct irdma_qp_uk is not used. So remove it.

Link: https://lore.kernel.org/r/20211021230612.153812-1-yanjun.zhu@linux.dev


Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>