Ticket History #1164: bogus return value from krb5_auth_con_genaddrs()

This code exists in krb5_auth_con_genaddrs():

if ((flags & KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR) ||
(flags & KRB5_AUTH_CONTEXT_GENERATE_REMOTE_ADDR)) {
if ((retval = getpeername(fd, (struct sockaddr *) &rsaddr, &ssize)))
return retval;

This is unfortunate because getpeername returns -1 and sets
errno on error; passing -1 to com_err gets you a useless "____ 255" as
your error message.

Returning errno would be an improvement over the current
situation, but returning something more meaningful would be even better.

Garry