FROMLIST: sched/wait: Fix a kthread_park race with wait_woken()

kthread_park and wait_woken have a similar race that kthread_stop and
wait_woken used to have before it was fixed in
cb6538e7. Extend that fix to also cover
kthread_park.

Bug: 274686101
Bug: 279016494
Link: https://lore.kernel.org/lkml/20230406194053.876844-1-arve@android.com/


Change-Id: Iaec960d7e30862f4ccac5c98dd43d32bbcf9a72b
Signed-off-by: Arve Hjønnevåg <arve@android.com>
(cherry picked from commit 69eba539)