Cosmetic fixes

- Changed Port#{asSwitchPort() -> getSwitchPort()}
- Added   Port#getPortNumber()
- Changed some formal param names: e.g., number -> portNumber

Change-Id: If93043489591e43e189137ee2f82907e863fdada
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
index dccef16..aa6642c 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
@@ -931,7 +931,7 @@
         for (Port port : topology.getPorts(dpid)) {
             log.warn("Port {} on Switch {} should be removed prior to removing Switch. Removing Port now.",
                     port, switchEvent);
-            PortEvent portEvent = new PortEvent(port.asSwitchPort());
+            PortEvent portEvent = new PortEvent(port.getSwitchPort());
             portsToRemove.add(portEvent);
         }
         for (PortEvent portEvent : portsToRemove) {