* scdaemon.c (main): Use estream_asprintf instead of asprintf.
* command.c (update_reader_status_file): Likewise.
(cmd_serialno): Use estream_asprintf instead of asprintf
and xfree instead of free to release memory allocated
through (estream_)asprintf.
(cmd_learn): Likewise.
(pin_cb): Likewise.
* app-openpgp.c (get_public_key): Likewise.