Fix javadoc:javadoc warnings

- Exclude org.openflow.* from generated javadoc
- Fix warnings

Change-Id: I47aefff15582c6eec05b864fb19613200d07df03
diff --git a/src/main/java/net/onrc/onos/core/packet/OnosLldp.java b/src/main/java/net/onrc/onos/core/packet/OnosLldp.java
index 7a53f0b..c3b2e8e 100644
--- a/src/main/java/net/onrc/onos/core/packet/OnosLldp.java
+++ b/src/main/java/net/onrc/onos/core/packet/OnosLldp.java
@@ -246,7 +246,7 @@
     /**
      * Sets switch DPID in LLDP packet.
      *
-     * @param sw the switch dpid
+     * @param dpid the switch dpid
      */
     public void setSwitch(Long dpid) {
         final byte[] byteDpid = ByteBuffer.allocate(8).putLong(dpid)
@@ -259,7 +259,7 @@
     /**
      * Sets the port number in LLDP packet.
      *
-     * @param port the port number
+     * @param portNumber the port number
      */
     public void setPort(short portNumber) {
         this.setPortTLV(portNumber);
@@ -279,6 +279,7 @@
      *
      * @return the serialized packet
      */
+    @Override
     public byte[] serialize() {
         return super.serialize();
     }