Merge branch 'idle-vtime-fixes-cleanups' into fixes

Pull a small idle/vtime series with two cputime accounting fixes plus
related cleanups and minor improvements.

* idle-vtime-fixes-cleanups:
  s390/idle: Remove psw_idle() prototype
  s390/vtime: Use lockdep_assert_irqs_disabled() instead of BUG_ON()
  s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE()
  s390/irq/idle: Remove psw bits early
  s390/idle: Inline update_timer_idle()
  s390/idle: Slightly optimize idle time accounting
  s390/idle: Add comment for non obvious code
  s390/vtime: Fix virtual timer forwarding
  s390/idle: Fix cpu idle exit cpu time accounting

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>