Enable checkstyle check for newline at the end of
source files and fix the errors found.

Change-Id: If1c8eb2127d2f2394157750e6bae7b94169c6bc4
diff --git a/src/main/java/net/onrc/onos/core/topology/LinkEvent.java b/src/main/java/net/onrc/onos/core/topology/LinkEvent.java
index 7434ad9..bf81f34 100644
--- a/src/main/java/net/onrc/onos/core/topology/LinkEvent.java
+++ b/src/main/java/net/onrc/onos/core/topology/LinkEvent.java
@@ -97,4 +97,4 @@
             return false;
         return true;
     }
-}
\ No newline at end of file
+}