scd: Clean up app_send_active_apps and app_send_card_list.
* scd/app.c (send_card_and_app_list): Only handle the case with WANTCARD=NULL. (app_send_card_list): Follow the change. (app_send_active_apps): Factor out the case with WANTCARD!=NULL.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>