kdc: Adjust error code mapping

Commit cbe156d927 mapped error code
HX509_CERT_REVOKED to KRB5_KDC_ERR_REVOKED_CERTIFICATE, so check for the latter
instead.

kdc/kerberos5.c

@@ -536,7 +536,7 @@ pa_pkinit_validate(astgs_request_t r, const PA_DATA *pa)
 
     ret = _kdc_pk_rd_padata(r, pa, &pkp);
     if (ret || pkp == NULL) {
-        if (ret == HX509_CERT_REVOKED) {
+        if (ret == KRB5_KDC_ERR_REVOKED_CERTIFICATE) {
             ret = KRB5_KDC_ERR_CLIENT_NOT_TRUSTED;
         } else {
             ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;