test/accept: fix a few errors
test/accept: fix a few errors

- Don't re-init the io_uring
- SQPOLL can fail with -EBADF or -EINVAL, depends on which path the
  sqe takes.

Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing