Move local variables to innermost possible scopes and use local
variables to cache calculations/reads done more than once.

No change in functionality (intended).
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <gregkh@suse.de>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>