Fix: crmadmin: return error if DC is not elected ClusterLabs#2902 Clu…

…sterLabs#3606

If the DC is not yet elected, the crmadmin will return an error.
(This change complements ClusterLabs#3606).

lib/pacemaker/pcmk_cluster_queries.c

@@ -234,8 +234,7 @@ designated_controller_event_cb(pcmk_ipc_api_t *controld_api,
     }
 
     reply = (const pcmk_controld_api_reply_t *) event_data;
-    out->message(out, "dc", reply->host_from);
-    data->rc = pcmk_rc_ok;
+    data->rc = out->message(out, "dc", reply->host_from);
 }
 
 /*!

lib/pacemaker/pcmk_output.c

@@ -887,9 +887,13 @@ dc(pcmk__output_t *out, va_list args)
 {
     const char *dc = va_arg(args, const char *);
 
-    return out->info(out, "Designated Controller is: %s",
+    int rc = out->info(out, "Designated Controller is: %s",
                      pcmk__s(dc, "not yet elected"));
-}
+    if (dc)
+        return rc;
+    else 
+        return pcmk_rc_undetermined;
+ }
 
 PCMK__OUTPUT_ARGS("dc", "const char *")
 static int