posix-timers: lock_timer: make it readable

Cleanup.  Imho makes the code much more understandable.  At least this
patch lessens both the source and compiled code.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: mingo@elte.hu
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>