agent,g10: Remove redundant SERIALNO request.
* agent/learncard.c (agent_handle_learn): Don't call agent_card_serialno. Get the serialno in status response. * g10/call-agent.c (agent_scd_learn): Don't request "SCD SERIALNO". (agent_scd_serialno): New. (card_cardlist_cb, agent_scd_cardlist): New.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>