Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu

Pull percpu update from Dennis Zhou:
 "Michael Cree noted generic UP Alpha has been broken since v3.18. This
  is a small fix for locking in UP percpu code that fixes the issue"

* 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu: convert spin_lock_irq to spin_lock_irqsave.