io_uring: change ring size calculation for CQE32

This changes the function rings_size to take large CQE's into account.

Co-developed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20220426182134.136504-4-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>