ONOS-2440: Simplify DistributedQueue implementation by leveraging state change notification support

Change-Id: Id0a48f07535d8b7e1d0f964bd1c0623ca81d4605
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseState.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseState.java
index 8b6db1e..b3dd1c4 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseState.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseState.java
@@ -21,7 +21,6 @@
 import java.util.Map.Entry;
 import java.util.Set;
 
-import org.onosproject.cluster.NodeId;
 import org.onosproject.store.service.Transaction;
 import org.onosproject.store.service.Versioned;
 
@@ -93,10 +92,10 @@
   byte[] queuePeek(String queueName);
 
   @Command
-  byte[] queuePop(String queueName, NodeId requestor);
+  byte[] queuePop(String queueName);
 
   @Command
-  Set<NodeId> queuePush(String queueName, byte[] entry);
+  void queuePush(String queueName, byte[] entry);
 
   @Query
   Long counterGet(String counterName);