* dirmngr/dns-stuff.c: Include dirmngr-err.h to set the correct error
source.
(get_h_errno_as_gpg_error): New.
(get_dns_cert_libdns): Fix error code.
(getsrv_libdns): Add arg R_COUNT and return an error code.
(getsrv_standard): Ditto.  Fix handling of res_query errors and
provide the correct size for the return buffer.
(getsrv): Adjust for changed worker functions.
(get_dns_cname_standard): Fix handling of res_query errors and provide
the correct size for the return buffer.