agent: Clear bogus pinentry cache, when it causes an error.
* agent/agent.h (PINENTRY_STATUS_*): Expose to public. (struct pin_entry_info_s): Add status. * agent/call-pinentry.c (agent_askpin): Clearing the ->status before the loop, let the assuan_transact set ->status. When failure with PINENTRY_STATUS_PASSWORD_FROM_CACHE, it returns soon. * agent/findkey.c (unprotect): Clear the pinentry cache, when it causes an error.
Cherry-picked from master commit of: