Javadoc fixes

Change-Id: Id23ed2d576b2222194153be9d043ca5acafe67ae
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/L2ModificationInstruction.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/L2ModificationInstruction.java
index a4176b1..0dbbb451 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/instructions/L2ModificationInstruction.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/L2ModificationInstruction.java
@@ -344,6 +344,7 @@
 
         /**
          * @deprecated in Drake Release.
+         * @return integer value of label
          */
         // Consider changing return value to MplsLabel
         // after deprecation process so that it'll be symmetric to