scd: Return GPG_ERR_PIN_BLOCKED when it's blocked.
* scd/app-openpgp.c (build_enter_admin_pin_prompt): Fix to use GPG_ERR_PIN_BLOCKED. (check_pin): Likewise.
Cherry-pick from master commit:
e6b3d53db36dba8aef640fc0a99cc079551a965a
- GnuPG-bug-id: T6425
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>