RFR(XS): JDK-8229375 Memory corruption in the implementation of the stack walk API

[Frederic Parain]

Greetings,

please review this one line change to fix a memory corruption
issue in the stack walk API implementation.

CR: https://bugs.openjdk.java.net/browse/JDK-8229375
Webrev: http://cr.openjdk.java.net/~fparain/8229375/webrev.00/index.html

Thank you,

Fred