Pull workqueue updates from Tejun Heo:
 "Workqueue has an early init trick where workqueues can be created and
  work items queued on them before the workqueue subsystem is online.
  This helps simplifying early init and operation of low level
  subsystems which use workqueues for managerial things which aren't
  depended upon early during boot.

  Out of laziness, the early init didn't cover workqueues with
  WQ_MEM_RECLAIM, which is inconsistent and confusing because adding the
  flag simply makes the system fail to boot. Cover WQ_MEM_RECLAIM too.

  This was originally brought up for RCU but RCU didn't actually need
  this. I still think it's a good idea to cover it"

* 'for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: allow WQ_MEM_RECLAIM on early init workqueues
  workqueue: separate out init_rescuer()