Pull CPU hotplug fix from Thomas Gleixner:
 "A fix for the CPU hotplug and cpusets interaction:

  cpusets delegate the hotplug work to a workqueue to prevent a lock
  order inversion vs. the CPU hotplug lock. The work is not flushed
  before the hotplug operation returns which creates user visible
  inconsistent state. Prevent this by flushing the work after dropping
  CPU hotplug lock and before releasing the outer mutex which serializes
  the CPU hotplug related sysfs interface operations"

* tag 'smp-urgent-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Cure the cpusets trainwreck