Remove link to tnameserv from CosNaming Javadoc API docs

The documentation for the tool tnameserv [1] has been removed from the JDK 11 documentation. The Javadoc API for the class CosNaming [2] points to this tool:

For an overview and examples of how to use the CosNaming API, please see:

    NamingService

Please remove the reference to tnameserv from the JDK 11 Javadoc API docs.

===========================

[1] https://docs.oracle.com/javase/10/tools/tnameserv.htm
[2] https://docs.oracle.com/javase/10/docs/api/org/omg/CosNaming/package-summary.html