kselftests: timers: Check _ALARM clockids are supported before suspending

It was reported that the alarmtimer-suspend test hangs on older
systems that don't support _ALARM clockids.

This is due to the fact that we don't check if the timer_create
fails, and thus when we suspend, the system will not programatically
resume.

Fix this by checking the timer_create call for errors.

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/timers/alarmtimer-suspend.c

@@ -152,7 +152,11 @@ int main(void)
 			alarm_clock_id++) {
 
 		alarmcount = 0;
-		timer_create(alarm_clock_id, &se, &tm1);
+		if (timer_create(alarm_clock_id, &se, &tm1) == -1) {
+			printf("timer_create failled, %s unspported?\n",
+					clockstring(alarm_clock_id));
+			break;
+		}
 
 		clock_gettime(alarm_clock_id, &start_time);
 		printf("Start time (%s): %ld:%ld\n", clockstring(alarm_clock_id),