ONOS-6084 Statistics were absent for the flows posted when device master was null. The issue is fixed with this code change

Change-Id: I15be1c65955e9ede797fa3438f70426db0c078a6
diff --git a/core/store/dist/src/main/java/org/onosproject/store/flow/impl/DistributedFlowRuleStore.java b/core/store/dist/src/main/java/org/onosproject/store/flow/impl/DistributedFlowRuleStore.java
index 83df014..59d476b 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/flow/impl/DistributedFlowRuleStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/flow/impl/DistributedFlowRuleStore.java
@@ -409,7 +409,7 @@
         NodeId master = mastershipService.getMasterFor(deviceId);
 
         if (master == null) {
-            log.warn("No master for {} : flows will be marked for removal", deviceId);
+            log.warn("No master for {} ", deviceId);
 
             updateStoreInternal(operation);