kselftests: timers:Remove unneeded semicolon

Eliminate the following coccinelle check warning:
tools/testing/selftests/timers/alarmtimer-suspend.c:82:2-3
Reported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NZhang Mingyu <zhang.mingyu@zte.com.cn>
Signed-off-by: NShuah Khan <skhan@linuxfoundation.org>

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

@@ -79,7 +79,7 @@ char *clockstring(int clockid)
 		return "CLOCK_BOOTTIME_ALARM";
 	case CLOCK_TAI:
 		return "CLOCK_TAI";
-	};
+	}
 	return "UNKNOWN_CLOCKID";
 }