<Swing Dev> [9] Review Request for 8039074: tidy warnings cleanup for javax.swing

[alexander stepanov]

Hello,

Could you please review the fix for the following bug:
https://bugs.openjdk.java.net/browse/JDK-8039074

Webrev corresponding:
http://cr.openjdk.java.net/~yan/8039074/webrev.00/

Just a minor cleanup of javadoc to avoid tidy warnings; no other code 
affected.

Thanks.