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

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.

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