Use Collection#forEach() instead of Stream#forEach() for simplicity

Change-Id: I0a1aea4bdb5d305c50273e6ff749fe71bd2a295a
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 368c06d..e21caa1 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
@@ -861,7 +861,7 @@
             try {
                 // compute a mapping from node to the set of devices whose flow entries it should backup
                 Map<NodeId, Set<DeviceId>> devicesToBackupByNode = Maps.newHashMap();
-                flowEntries.keySet().stream().forEach(deviceId -> {
+                flowEntries.keySet().forEach(deviceId -> {
                     List<NodeId> backupNodes = getBackupNodes(deviceId);
                     backupNodes.forEach(backupNode -> {
                             if (lastBackupTimes.getOrDefault(new BackupOperation(backupNode, deviceId), 0L)