RDMA/rxe: Shorten pool names in rxe_pool.c

Replace pool names like "rxe-xx" with "xx". Just reduces clutter.

Link: https://lore.kernel.org/r/20220304000808.225811-8-rpearsonhpe@gmail.com


Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>