test/poll: ignore parent dying
test/poll: ignore parent dying

The parent may well die before the child is done, as long as it wrote to
the pipe, we're fine.

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

axboe/liburing,axboe/liburing,axboe/liburing