RFR 8208604: Metadata::print_value_string() compares 'this' to NULL

[Harold David Seigel]

Hi,

Please review this JDK-12 fix for JDK-8208604.  The fix removes the 
comparison between 'this' and 'NULL' from function 
Metadata::print_value_string().

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8208604/webrev/index.html

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8208604

This fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-x64, Windows, and Mac OS X, running tiers 3-5 tests on 
Linux-x64, and by running JCK-11 API, Lang and VM tests on Linux-x64.

Thanks, Harold