Fixed a slew of shutdown exceptions that arose due to improper or out-of-order resource clean-up, e.g. listeners, timers, executors.

Change-Id: I37c351c4202b32e92c076d9d566b96d7ff8d313a
diff --git a/providers/openflow/device/src/main/java/org/onosproject/provider/of/device/impl/OpenFlowDeviceProvider.java b/providers/openflow/device/src/main/java/org/onosproject/provider/of/device/impl/OpenFlowDeviceProvider.java
index eb72230..c0dc9f8 100644
--- a/providers/openflow/device/src/main/java/org/onosproject/provider/of/device/impl/OpenFlowDeviceProvider.java
+++ b/providers/openflow/device/src/main/java/org/onosproject/provider/of/device/impl/OpenFlowDeviceProvider.java
@@ -268,8 +268,8 @@
             providerService.deviceConnected(did, description);
             providerService.updatePorts(did, buildPortDescriptions(sw));
 
-            PortStatsCollector psc = new PortStatsCollector(
-                        controller.getSwitch(dpid), POLL_INTERVAL);
+            PortStatsCollector psc =
+                    new PortStatsCollector(controller.getSwitch(dpid), POLL_INTERVAL);
             psc.start();
             collectors.put(dpid, psc);
         }
@@ -314,7 +314,7 @@
         /**
          * Translates a RoleState to the corresponding MastershipRole.
          *
-         * @param response
+         * @param response role state
          * @return a MastershipRole
          */
         private MastershipRole roleOf(RoleState response) {
@@ -334,7 +334,6 @@
         /**
          * Builds a list of port descriptions for a given list of ports.
          *
-         * @param ports the list of ports
          * @return list of portdescriptions
          */
         private List<PortDescription> buildPortDescriptions(OpenFlowSwitch sw) {