BugFix: casting iterator to Device?

Change-Id: I21c0e4a110e5aa8c9c5708761a4fbfb5c83ea0f5
diff --git a/src/test/java/net/onrc/onos/core/topology/TopologyImplTest.java b/src/test/java/net/onrc/onos/core/topology/TopologyImplTest.java
index cc7ac9c..d604011 100644
--- a/src/test/java/net/onrc/onos/core/topology/TopologyImplTest.java
+++ b/src/test/java/net/onrc/onos/core/topology/TopologyImplTest.java
@@ -239,7 +239,7 @@
         for (long switchID = 1; switchID <= TEST_SWITCH_NUM; switchID++) {
             Iterator<Device> itr = testTopology.getSwitch(new Dpid(switchID)).getDevices().iterator();
             while (itr.hasNext()) {
-                testTopology.removeDevice((Device) itr);
+                testTopology.removeDevice(itr.next());
             }
             testTopology.removeSwitch(switchID);