scd: Don't release the context until list_finish for PC/SC.
* scd/apdu.c (apdu_dev_list_start): Increment PCSC.COUNT here. (apdu_dev_list_finish): Decrement PCSC.COUNT.
- GnuPG-bug-id: T5416
- Fixes-commit: 32baa9acfb153004bdb2509f9516482b78f256a4
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>