scd: Add explict functions for 'app' reference counting.
* scd/app.c (app_ref): New. (app_unref): New. (release_application): Renamed to ... (app_unref_locked): this and remove arg locked_already. Change callers to use this or app_ref. * scd/command.c (open_card_with_request): (cmd_pksign, cmd_pkauth, cmd_pkdecrypt): Use app_ref and app_unref instead of accessing the counter directly.
This is better in case we need to debug stuff. There is a real change
however: We now lock and unlock the app before changing the reference
The whole app locking business should be reviewed because we pass
pointers along without immediately bumping the refcount.
- Signed-off-by: Werner Koch <firstname.lastname@example.org>