Exception at removeUnreportedFlows in StatisticsManagerImpl

This bug is found in stable/lithium and also main.

2015-07-07 14:37:15,748 | WARN | ds-oper-thread-0 | StatisticsManagerImpl | 264 - org.opendaylight.openflowplugin.applications.statistics-manager - 0.1.1.SNAPSHOT | Unhandled exception during processing statistics. Restarting transaction chain.
java.lang.NullPointerException
at org.opendaylight.openflowplugin.applications.statistics.manager.impl.StatListenCommitFlow$TableFlowUpdateState.removeUnreportedFlows(StatListenCommitFlow.java:464)[264:org.opendaylight.openflowplugin.applications.statistics-manager:0.1.1.SNAPSHOT]
at org.opendaylight.openflowplugin.applications.statistics.manager.impl.StatListenCommitFlow.statsFlowCommitAll(StatListenCommitFlow.java:262)[264:org.opendaylight.openflowplugin.applications.statistics-manager:0.1.1.SNAPSHOT]
at org.opendaylight.openflowplugin.applications.statistics.manager.impl.StatListenCommitFlow.access$000(StatListenCommitFlow.java:82)[264:org.opendaylight.openflowplugin.applications.statistics-manager:0.1.1.SNAPSHOT]
at org.opendaylight.openflowplugin.applications.statistics.manager.impl.StatListenCommitFlow$2.applyOperation(StatListenCommitFlow.java:208)[264:org.opendaylight.openflowplugin.applications.statistics-manager:0.1.1.SNAPSHOT]

After the exception, there were side-effect null pointer exceptions whenever there were statistics poll.

The fix is simple:
diff --git a/applications/statistics-manager/src/main/java/org/opendaylight/open
index 71d34dc..2180e09 100644
— a/applications/statistics-manager/src/main/java/org/opendaylight/openflowplu
+++ b/applications/statistics-manager/src/main/java/org/opendaylight/openflowplu
@@ -461,7 +461,7 @@ public class StatListenCommitFlow extends StatAbstractListen
final InstanceIdentifier<Flow> flowRef = tableRef.child(Flow.cl
if (nodeDeleteMap != null && flowKey.getId().getValue().startsW
final Integer lifeIndex = nodeDeleteMap.get(flowRef);

• if (lifeIndex > 0) {
  + if (lifeIndex != null && lifeIndex > 0) { break; }

  else {
  nodeDeleteMap.remove(flowRef);