Make Logger instance final as SL4J suggests
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
index 7550b37..3178b60 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
@@ -26,7 +26,7 @@
  * Class for performing Flow-related operations on the Database.
  */
 class FlowDatabaseOperation {
-    private static Logger log = LoggerFactory.getLogger(FlowDatabaseOperation.class);
+    private final static Logger log = LoggerFactory.getLogger(FlowDatabaseOperation.class);
 
     /**
      * Add a flow.