scd: Distinguish cancel by user and protocol error.
* scd/apdu.h (SW_HOST_CANCELLED): New. * scd/apdu.c (host_sw_string): Support SW_HOST_CANCELLED. (pcsc_error_to_sw): Return SW_HOST_CANCELLED for PCSC_E_CANCELLED. * scd/iso7816.c (map_sw): Return GPG_ERR_INV_RESPONSE for SW_HOST_ABORTED and GPG_ERR_CANCELED for SW_HOST_CANCELLED.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>