Fixing a minor stylistic issue.

Change-Id: I57b6e44e03c576be88c5f130f852d5ca5bcb00c9
diff --git a/core/api/src/main/java/org/onosproject/store/service/DocumentTree.java b/core/api/src/main/java/org/onosproject/store/service/DocumentTree.java
index 72e10bf..35c6deb 100644
--- a/core/api/src/main/java/org/onosproject/store/service/DocumentTree.java
+++ b/core/api/src/main/java/org/onosproject/store/service/DocumentTree.java
@@ -23,7 +23,7 @@
 /**
  * A hierarchical <a href="https://en.wikipedia.org/wiki/Document_Object_Model">document tree</a> data structure.
  *
- * @param V document tree value type
+ * @param <V> document tree value type
  */
 public interface DocumentTree<V> {