Fix some minor compiler warnings.
* src/agent.c (agent_configure): Avoid dead stores. (unhexify_fpr): Likewise. (get_cert_data_cb): Drop unused variable. * src/gpgsm.c (search_cb): Avoid dead store. * tests/t-gettokeninfo.c (main): Fail on error.
- Signed-off-by: Justus Winter <justus@g10code.com>