staging: kpc2000: clean up after probe failure.

On error, kp2000_probe_cores just returned an error without freeing
resources which had previously been allocated.  Added the missing
clean-up code.

Updated TODO.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>