fixed checkstyle violation: Expected @param tag for 'elementName'.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1212046 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/digester3/binder/NestedPropertiesBuilder.java b/src/main/java/org/apache/commons/digester3/binder/NestedPropertiesBuilder.java
index f2c021d..7b10cda 100644
--- a/src/main/java/org/apache/commons/digester3/binder/NestedPropertiesBuilder.java
+++ b/src/main/java/org/apache/commons/digester3/binder/NestedPropertiesBuilder.java
@@ -77,7 +77,7 @@
     /**
      * Allows element2property mapping to be overridden.
      *
-     * @param elementName
+     * @param elementName The child xml element to match
      * @return the property alias builder
      * @since 3.2
      */