Fix issues found by FindBugs: WMI_WRONG_MAP_ITERATOR

http://findbugs.sourceforge.net/bugDescriptions.html#WMI_WRONG_MAP_ITERATOR

Change-Id: I3fdc5bb1df8531654ffee9645cb6fbfde4661022
diff --git a/src/main/java/net/onrc/onos/core/intent/runtime/PlanCalcRuntime.java b/src/main/java/net/onrc/onos/core/intent/runtime/PlanCalcRuntime.java
index a671d7a..6636be2 100644
--- a/src/main/java/net/onrc/onos/core/intent/runtime/PlanCalcRuntime.java
+++ b/src/main/java/net/onrc/onos/core/intent/runtime/PlanCalcRuntime.java
@@ -131,8 +131,9 @@
         // really simple first iteration of plan
         //TODO: optimize the map in phases
         Set<FlowEntry> phase = new HashSet<>();
-        for (FlowEntry e : map.keySet()) {
-            Integer i = map.get(e);
+        for (Map.Entry<FlowEntry, Integer> entry : map.entrySet()) {
+            FlowEntry e = entry.getKey();
+            Integer i = entry.getValue();
             if (i == 0) {
                 continue;
             } else if (i > 0) {