Follow the convention for Javadoc

Change-Id: If8d563807a2af99d049601078ddd715aea3132f3
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
index f276c0d..cb9a248 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
@@ -51,6 +51,7 @@
 
     /**
      * Obtains a globally unique next objective.
+     *
      * @return an integer
      */
     int allocateNextId();