workqueue: set delayed_work->timer function on initialization

delayed_work->timer.function is currently initialized during
queue_delayed_work_on().  Export delayed_work_timer_fn() and set
delayed_work timer function during delayed_work initialization
together with other fields.

This ensures the timer function is always valid on an initialized
delayed_work.  This is to help mod_delayed_work() implementation.

To detect delayed_work users which diddle with the internal timer,
trigger WARN if timer function doesn't match on queue.

Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: cosmetic whitespace updates for macro definitions

Consistently use the last tab position for '\' line continuation in
complex macro definitions.  This is to help the following patches.

This patch is cosmetic.

Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: make deferrable delayed_work initializer names consistent

Initalizers for deferrable delayed_work are confused.

* __DEFERRED_WORK_INITIALIZER()
* DECLARE_DEFERRED_WORK()
* INIT_DELAYED_WORK_DEFERRABLE()

Rename them to

* __DEFERRABLE_WORK_INITIALIZER()
* DECLARE_DEFERRABLE_WORK()
* INIT_DEFERRABLE_WORK()

This patch doesn't cause any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>

Conflicts:
	drivers/cpufreq/cpufreq_conservative.c
	drivers/cpufreq/cpufreq_ondemand.c

Conflicts:
	drivers/cpufreq/cpufreq_conservative.c
	drivers/cpufreq/cpufreq_ondemand.c
Replace all ramaining INIT_DELAYED_WORK_DEFERRABLE with new define -->