io_uring: fix false WARN_ONCE

mainline inclusion
from mainline-v5.13-rc6
commit e6ab8991
category: bugfix
bugzilla: 186576, https://gitee.com/openeuler/kernel/issues/I554BJ


CVE: NA

--------------------------------

io_uring: fix false WARN_ONCE

WARNING: CPU: 1 PID: 11749 at fs/io-wq.c:244 io_wqe_wake_worker fs/io-wq.c:244 [inline]
WARNING: CPU: 1 PID: 11749 at fs/io-wq.c:244 io_wqe_enqueue+0x7f6/0x910 fs/io-wq.c:751

A WARN_ON_ONCE() in io_wqe_wake_worker() can be triggered by a valid
userspace setup. Replace it with pr_warn.

Reported-by:  <syzbot+ea2f1484cffe5109dc10@syzkaller.appspotmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f7ede342c3342c4c26668f5168e2993e38bbd99c.1623949695.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>