RDMA/siw: Call orq_get_current if possible

Use orq_get_current() in siw_orq_empty().

Link: https://lore.kernel.org/r/20231203092655.28102-5-guoqing.jiang@linux.dev


Acked-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>