RFR(XS) JDK10: 8196678: avoid printing uninitialized buffer in os::print_memory_info on AIX

[Langer, Christoph]

Hi,

Arno has spotted an issue when printing hs_err files on AIX. This fix should still be done for JDK10. Please review and approve.

Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8196678.0/
Bug: https://bugs.openjdk.java.net/browse/JDK-8196678

Thanks
Christoph