Fix function prototypes to match ones in libassuan.
* src/assuan-support.c (my_read, my_write): Use ssize_t. (my_socket, my_connect): Use int instead of assuan_fd_t for older libassuan. * tests/gpg/t-encrypt-large.c (read_cb, write_cb): Use gpgme_ssize_t.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>