hg: portola/portola/hotspot: Handle confstr version lookup failures gracefully

[mikael.vidstedt at oracle.com]

Changeset: 2a55f49c4afc
Author:    mikael
Date:      2017-04-11 16:59 -0700
URL:       http://hg.openjdk.java.net/portola/portola/hotspot/rev/2a55f49c4afc

Handle confstr version lookup failures gracefully

! src/os/linux/vm/os_linux.cpp