Sonar suggestions - fixes to potential null pointer dereferences

Change-Id: I4e350a9d72a9322971d5d4f831f1bdf167986b87
diff --git a/apps/restconf/restconfmgr/src/main/java/org/onosproject/restconf/restconfmanager/RestconfManager.java b/apps/restconf/restconfmgr/src/main/java/org/onosproject/restconf/restconfmanager/RestconfManager.java
index 5334cd0..1b6a589 100644
--- a/apps/restconf/restconfmgr/src/main/java/org/onosproject/restconf/restconfmanager/RestconfManager.java
+++ b/apps/restconf/restconfmgr/src/main/java/org/onosproject/restconf/restconfmanager/RestconfManager.java
@@ -312,7 +312,8 @@
             }
             parentId = rid.copyBuilder().removeLastKey().build();
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
+            log.error("getDataForStore()", e);
+            return null;
         }
         ResourceData.Builder resData = DefaultResourceData.builder();
         resData.addDataNode(dbr.build());