JDK 14 RFR of JDK-8231777: Remove extraneous @serial javadoc tag in NodeChangeEvent.java

[Joe Darcy]

Hello,

In response to the review of JDK-8231546:

http://mail.openjdk.java.net/pipermail/core-libs-dev/2019-September/062612.html

it was noticed a field in NodeChangeEvent.java has an @serial javadoc 
tag, but the class itself is @serial excluded so the @serial tag on the 
field is extraneous.

Please review the removal of the extraneous tag:

diff -r 91d236715160 
src/java.prefs/share/classes/java/util/prefs/NodeChangeEvent.java
--- a/src/java.prefs/share/classes/java/util/prefs/NodeChangeEvent.java 
Tue Oct 01 20:07:30 2019 -0700
+++ b/src/java.prefs/share/classes/java/util/prefs/NodeChangeEvent.java 
Wed Oct 02 17:05:48 2019 -0700
@@ -46,8 +46,6 @@
  public class NodeChangeEvent extends java.util.EventObject {
      /**
       * The node that was added or removed.
-     *
-     * @serial
       */
      private transient Preferences child;

Thanks,

-Joe