Fix Javadoc warnings

Change-Id: I2975b3d7bb581d5574969037e1f99401b94ef3dc
diff --git a/apps/demo/src/main/java/org/onosproject/demo/DemoAPI.java b/apps/demo/src/main/java/org/onosproject/demo/DemoAPI.java
index 5812eeb..eded291 100644
--- a/apps/demo/src/main/java/org/onosproject/demo/DemoAPI.java
+++ b/apps/demo/src/main/java/org/onosproject/demo/DemoAPI.java
@@ -28,7 +28,9 @@
 
     /**
      * Tests flow subsystem based on the parameters supplied.
+     *
      * @param params the test parameters
+     * @return JSON representation
      */
     JsonNode flowTest(Optional<JsonNode> params);
 
diff --git a/core/api/src/main/java/org/onosproject/net/flow/CompletedBatchOperation.java b/core/api/src/main/java/org/onosproject/net/flow/CompletedBatchOperation.java
index fce7ee9..b9c1387 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/CompletedBatchOperation.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/CompletedBatchOperation.java
@@ -54,6 +54,7 @@
      *
      * @param success  indicates whether the completion is successful.
      * @param failures set of any failures encountered
+     * @param deviceId device id
      */
     public CompletedBatchOperation(boolean success, Set<? extends FlowRule> failures,
                                    DeviceId deviceId) {
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseService.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseService.java
index 6f2b655..2ae418b 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseService.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseService.java
@@ -10,9 +10,11 @@
     /**
      * Creates a ConsistentMap.
      *
+     * @param <K> Key type
+     * @param <V> value type
      * @param name map name
      * @param serializer serializer to use for serializing keys and values.
      * @return consistent map.
      */
     <K, V> ConsistentMap<K , V> createConsistentMap(String name, StoreSerializer serializer);
-}
\ No newline at end of file
+}