io_uring/sqpoll: Do not set PF_NO_SETAFFINITY on sqpoll threads

Users may specify a CPU where the sqpoll thread would run. This may
conflict with cpuset operations because of strict PF_NO_SETAFFINITY
requirement. That flag is unnecessary for polling "kernel" threads, see
the reasoning in commit 01e68ce0 ("io_uring/io-wq: stop setting
PF_NO_SETAFFINITY on io-wq workers"). Drop the flag on poll threads too.

Fixes: 01e68ce0 ("io_uring/io-wq: stop setting PF_NO_SETAFFINITY on io-wq workers")
Link: https://lore.kernel.org/all/20230314162559.pnyxdllzgw7jozgx@blackpad/Signed-off-by: Michal Koutný <mkoutny@suse.com>
Link: https://lore.kernel.org/r/20230314183332.25834-1-mkoutny@suse.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/sqpoll.c

@@ -233,7 +233,6 @@ static int io_sq_thread(void *data)
 		set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
 	else
 		set_cpus_allowed_ptr(current, cpu_online_mask);
-	current->flags |= PF_NO_SETAFFINITY;
 
 	mutex_lock(&sqd->lock);
 	while (1) {