Make Logger instance final as SL4J suggests
diff --git a/src/test/java/net/onrc/onos/ofcontroller/core/internal/LinkStorageImplTest.java b/src/test/java/net/onrc/onos/ofcontroller/core/internal/LinkStorageImplTest.java
index 9b1c4d6..fcc753f 100644
--- a/src/test/java/net/onrc/onos/ofcontroller/core/internal/LinkStorageImplTest.java
+++ b/src/test/java/net/onrc/onos/ofcontroller/core/internal/LinkStorageImplTest.java
@@ -40,7 +40,7 @@
 @RunWith(PowerMockRunner.class)
 @PrepareForTest({LinkStorageImpl.class, GraphDBConnection.class, GraphDBOperation.class})
 public class LinkStorageImplTest {
-	protected static Logger log = LoggerFactory.getLogger(LinkStorageImplTest.class);
+	protected final static Logger log = LoggerFactory.getLogger(LinkStorageImplTest.class);
 
 	private static ILinkStorage linkStorage;