Addressed some checkstyle, PMD and findbugs violations in the ARP module

Change-Id: I194533ba5f96a7631ea662a93cbcbd8a2c84dea9
diff --git a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/PacketOutNotification.java b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/PacketOutNotification.java
index 3d37d25..a201939 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/PacketOutNotification.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/PacketOutNotification.java
@@ -4,18 +4,21 @@
 
 /**
  * A PacketOutNotification contains data sent between ONOS instances that
- * directs other instances to send a packet out a set of ports.
- * This is an abstract base class that will be subclassed by specific
- * types of notifications.
- *
+ * directs other instances to send a packet out a set of ports. This is an
+ * abstract base class that will be subclassed by specific types of
+ * notifications.
  */
 public abstract class PacketOutNotification implements Serializable {
 
-	private static final long serialVersionUID = 1L;
-	
-	protected final byte[] packet;
+    private static final long serialVersionUID = 1L;
 
-	public PacketOutNotification(byte[] packet) {
-		this.packet = packet;
-	}
+    protected final byte[] packet;
+
+    /**
+     * Class constructor.
+     * @param packet the packet data to send in the packet-out
+     */
+    public PacketOutNotification(byte[] packet) {
+        this.packet = packet;
+    }
 }