agent: Clean up for getting info from SEXP.
* agent/agent.h (agent_is_dsa_key, agent_is_eddsa_key): Remove. (agent_pk_get_algo): New. * agent/findkey.c (agent_pk_get_algo): New. * agent/pksign.c (do_encode_dsa): Use generic GCRY_PK_ECC. (agent_pksign_do): Use agent_pk_get_algo.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>