scd: Clean up unused shutdown method.
* scd/apdu.c (shutdown_ccid_reader, apdu_shutdown_reader): Remove. (reset_ccid_reader): Don't set shutdown_reader. * scd/ccid-driver.c (ccid_shutdown_reader): Remove.
Backport of master commit: d1ae7103352fbda2a05f098379cd3043a0ab5566
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>