Prints when a host command returns an error code.
When 'hcdebug on', hex-dumps the host command params and response.
BUG=none
TEST=manual (> is ec console, $ is root shell)
$ ectool gpioget foobar --> EC console shows error 2 returned
> hcdebug on
$ ectool hello --> EC console shows params and response as hex
> hcdebug off
$ ectool hello --> no extra output on EC debug console
Change-Id: I2dbc77be5b59125f394d970cf1c83c2a976e926e
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/28948
Reviewed-by: Bill Richardson <wfrichar@chromium.org>