staging: alarm-dev: information leak in alarm_ioctl()

Smatch complains that if we pass an invalid clock type then "ts" is
never set.  We need to check for errors earlier, otherwise we end up
passing uninitialized stack data to userspace.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>