io_uring: add reschedule point to handle_tw_list()

io_uring: add reschedule point to handle_tw_list()

commit 68aab7f33d7ef1d52b88000fa6afdc3d648a55ff upstream.

If CONFIG_PREEMPT_NONE is set and the task_work chains are long, we
could be running into issues blocking others for too long. Add a
reschedule check in handle_tw_list(), and flush the ctx if we need to
reschedule.

Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Jens Axboe <axboe@kernel.dk>