RFR (T) 8172485: [TESTBUG] RedefineLeak.java runs out of metaspace memory

[coleen.phillimore at oracle.com]

Summary: Check for zero exit value.

It doesn't run out of memory anymore.  Bugs appears down for 
maintenance, but that's what I said there too.

Ran tier2 on all Oracle platforms, where the test is run.

open webrev at http://cr.openjdk.java.net/~coleenp/2020/8172485.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8172485

Thanks,
Coleen