RDMA/rxe: remove the unnecessary variable

In the struct rxe_qp, the variable send_pkts is never used.  So remove it.

Link: https://lore.kernel.org/r/20210915075128.482919-1-yanjun.zhu@intel.com


Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>