ONOS-2381 Fixing intent purge command

We need to remove the current value.

Change-Id: Ib15f9b097e3df096b45367012d067973436e1d85

@@ -281,6 +281,7 @@ public class IntentData { //FIXME need to make this "immutable"
             return true;
 
         case PURGE_REQ:
+            // TODO we should enforce that only WITHDRAWN intents can be purged
             return true;
 
         case COMPILING:

@@ -180,7 +180,7 @@ public class GossipIntentStore
             // Only the master is modifying the current state. Therefore assume
             // this always succeeds
             if (newData.state() == PURGE_REQ) {
-                currentMap.remove(newData.key(), newData);
+                currentMap.remove(newData.key(), currentData);
             } else {
                 currentMap.put(newData.key(), new IntentData(newData));
             }