VOL-1774 Etcd Crash Handling

Change-Id: I1eeb726654c3972fd0a4fafae134607e5a810415
diff --git a/ro_core/core/logical_device_manager.go b/ro_core/core/logical_device_manager.go
index 97bc603..fc09f12 100644
--- a/ro_core/core/logical_device_manager.go
+++ b/ro_core/core/logical_device_manager.go
@@ -103,7 +103,11 @@
 func (ldMgr *LogicalDeviceManager) listLogicalDevices() (*voltha.LogicalDevices, error) {
 	log.Debug("ListAllLogicalDevices")
 	result := &voltha.LogicalDevices{}
-	if logicalDevices := ldMgr.clusterDataProxy.List(context.Background(), "/logical_devices", 0, false, ""); logicalDevices != nil {
+	if logicalDevices, err := ldMgr.clusterDataProxy.List(context.Background(), "/logical_devices", 0, false,
+		""); err != nil {
+		log.Errorw("failed-to-list-devices", log.Fields{"error": err})
+		return nil, err
+	} else if logicalDevices != nil {
 		for _, logicalDevice := range logicalDevices.([]interface{}) {
 			result.Items = append(result.Items, logicalDevice.(*voltha.LogicalDevice))
 		}