* agent/call-pinentry.c (unlock_pinentry): Add error logging. Map
error source of uncommon errors to Pinentry.
--
With this change it is possible to detect whether an error like
GPG_ERR_ASS_INV_RESPONSE has its origin in a call to Pinentry or comes
from another part of gpg-agent.
Signed-off-by: Werner Koch <wk@gnupg.org>