io_uring/io-wq: only free worker if it was allocated for creation

stable inclusion
from stable-v5.10.164
commit a88a0d16e18f18d7221f0c5a1fdf487f5f9079e3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7T7G4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a88a0d16e18f18d7221f0c5a1fdf487f5f9079e3



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commit e6db6f93 upstream.

We have two types of task_work based creation, one is using an existing
worker to setup a new one (eg when going to sleep and we have no free
workers), and the other is allocating a new worker. Only the latter
should be freed when we cancel task_work creation for a new worker.

Fixes: af82425c ("io_uring/io-wq: free worker if task_work creation is canceled")
Reported-by:  <syzbot+d56ec896af3637bdb7e4@syzkaller.appspotmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>