Correct Javadoc code example (#1400)

* Javadoc: Add type to suppress "Raw use of parameterized class" warning

* Javadoc: Remove usage of constructor since it has been deprecated

* Javadoc: Remove extra closing parentheses

* Javadoc: Need second build() method to return a DiffResult as the first build method returns a ReflectionDiffBuilder

---------

Co-authored-by: Ken Dombeck <[email protected]>

Author: kdombeck

src/main/java/org/apache/commons/lang3/builder/DiffBuilder.java

@@ -41,12 +41,12 @@
  *
  *   ...
  *
- *   public DiffResult diff(Person obj) {
+ *   public DiffResult<Person> diff(Person obj) {
  *     // No need for null check, as NullPointerException correct if obj is null
- *     return new DiffBuilder.<Person>builder()
+ *     return DiffBuilder.<Person>builder()
  *         .setLeft(this)
  *         .setRight(obj)
- *         .setStyle(ToStringStyle.SHORT_PREFIX_STYLE))
+ *         .setStyle(ToStringStyle.SHORT_PREFIX_STYLE)
  *         .build()
  *       .append("name", this.name, obj.name)
  *       .append("age", this.age, obj.age)

src/main/java/org/apache/commons/lang3/builder/ReflectionDiffBuilder.java

@@ -43,15 +43,16 @@
  *   boolean smoker;
  *   ...
  *
- *   public DiffResult diff(Person obj) {
+ *   public DiffResult<Person> diff(Person obj) {
  *     // No need for null check, as NullPointerException correct if obj is null
- *     return new ReflectionDiffBuilder.<Person>builder()
+ *     return ReflectionDiffBuilder.<Person>builder()
  *       .setDiffBuilder(DiffBuilder.<Person>builder()
  *           .setLeft(this)
  *           .setRight(obj)
  *           .setStyle(ToStringStyle.SHORT_PREFIX_STYLE)
  *           .build())
  *       .setExcludeFieldNames("userName", "password")
+ *       .build()
  *       .build();
  *   }
  * }