Make Logger instance final as SL4J suggests
diff --git a/src/test/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImplTest.java b/src/test/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImplTest.java
index e266d4a..cc77f14 100644
--- a/src/test/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImplTest.java
+++ b/src/test/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImplTest.java
@@ -76,7 +76,7 @@
 
 public class DeviceManagerImplTest extends FloodlightTestCase {
 
-    protected static Logger logger =
+    protected final static Logger logger =
             LoggerFactory.getLogger(DeviceManagerImplTest.class);
 
     protected OFPacketIn packetIn_1, packetIn_2, packetIn_3;