staging: kpc2000: report error status to spi core

There is an error condition that's not reported to
the spi core in kp_spi_transfer_one_message().
It should restore status value to m->status, and
return it in error path.

Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>