io_uring: open code io_put_req_find_next

There is only one user of io_put_req_find_next() and it doesn't make
much sense to have it. Open code the function.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/38b5c5e48e4adc8e6a0cd16fdd5c1531d7ff81a9.1687518903.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>