Make Logger instance final as SL4J suggests
diff --git a/src/main/java/net/onrc/onos/ofcontroller/util/serializers/DpidDeserializer.java b/src/main/java/net/onrc/onos/ofcontroller/util/serializers/DpidDeserializer.java
index 9075f96..fe93245 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/util/serializers/DpidDeserializer.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/util/serializers/DpidDeserializer.java
@@ -17,7 +17,7 @@
  */
 public class DpidDeserializer extends JsonDeserializer<Dpid> {
 
-    protected static Logger log = LoggerFactory.getLogger(DpidDeserializer.class);
+    protected final static Logger log = LoggerFactory.getLogger(DpidDeserializer.class);
 
     @Override
     public Dpid deserialize(JsonParser jp,