workqueue: Use rcu_read_lock_any_held() instead of rcu_read_lock_held()

The different flavors of RCU read critical sections have been unified. Let's
update the locking assertion macros accordingly to avoid requiring
unnecessary explicit rcu_read_[un]lock() calls.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>