Fix Javadoc warnings

Change-Id: Ia5fe7785f76da92abbf940599cbd3d7dc6ac2cc5
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PointToPointIntentCompiler.java b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PointToPointIntentCompiler.java
index 3b018c3..ee5f4e2 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PointToPointIntentCompiler.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PointToPointIntentCompiler.java
@@ -336,6 +336,9 @@
 
     /**
      * Creates group key unique to each intent.
+     *
+     * @param intentId identifier of intent to get a key for
+     * @return unique group key for the intent identifier
      */
     public static GroupKey makeGroupKey(IntentId intentId) {
         ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);