io_uring_wait_cqes: use cqe related return codes

Some churn here again... After thinking about this for a bit, I don't
think this function should deviate from the other wait functions. That
means we return 0 for success, and -errno on error. The fact that we
may need to submit is somewhat irrelevant.

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