Use io_uring_prep_rw in io_uring_prep_cancel
Use io_uring_prep_rw in io_uring_prep_cancel

follow liburing's API as closely as possible.

Signed-off-by: Hiroaki Nakamura <d5f119c83b49083ce2220cbef65198e8f74dd9e4@gmail.com>

andrewrk/zig,andrewrk/zig