man/io_uring_setup.2: improve SQPOLL wakeup example

This makes it consistent with how liburing uses it, instead of using
the sledge hammer that is a fully SMP memory barrier on archs that
don't need it.

Reported-by: Joran Dirk Greef <joran@coil.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 file changed