alarmtimer: Remove unused but set variable

Remove the set but unused variable base in alarm_clock_get to fix the
following warning when building with 'W=1':

  kernel/time/alarmtimer.c: In function ‘alarm_timer_create’:
  kernel/time/alarmtimer.c:545:21: warning: variable ‘base’ set but not used [-Wunused-but-set-variable]
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20161017094702.10873-1-tklauser@distanz.chSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/time/alarmtimer.c

@@ -542,7 +542,6 @@ static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
 static int alarm_timer_create(struct k_itimer *new_timer)
 {
 	enum  alarmtimer_type type;
-	struct alarm_base *base;
 
 	if (!alarmtimer_get_rtcdev())
 		return -ENOTSUPP;
@@ -551,7 +550,6 @@ static int alarm_timer_create(struct k_itimer *new_timer)
 		return -EPERM;
 
 	type = clock2alarm(new_timer->it_clock);
-	base = &alarm_bases[type];
 	alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
 	return 0;
 }