We have used the error status from c-ares to decide whether to mark the
request as failed or not. This is wrong, but mostly worked fine because
we have been getting some error code from c-ares in all situations until
we added the per-request timeouts. We should use the errno code and only
use the c-ares return code to print extended debugging information.
https://fedorahosted.org/sssd/ticket/1274