rtc alarm: fix bad index when canceling alarms[]

It was using ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK as an
index.

Change-Id: I919860cc71254453e382616bce9fd5455802cb3d
Signed-off-by: JP Abgrall <jpa@google.com>
diff --git a/drivers/rtc/alarm.c b/drivers/rtc/alarm.c
index e0e98dd..28b0df8 100644
--- a/drivers/rtc/alarm.c
+++ b/drivers/rtc/alarm.c
@@ -389,7 +389,7 @@
 
 	hrtimer_cancel(&alarms[ANDROID_ALARM_RTC_WAKEUP].timer);
 	hrtimer_cancel(&alarms[
-			ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK].timer);
+			ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].timer);
 
 	tmp_queue = &alarms[ANDROID_ALARM_RTC_WAKEUP];
 	if (tmp_queue->first)