hg: bsd-port/jdk8/hotspot: . Fix compilation warning from change in _id type. Allows build

[kurt at intricatesoftware.com]

Changeset: 062571963acf
Author:    Kurt Miller <kurt at intricatesoftware.com>
Date:      2019-01-21 20:43 -0500
URL:       http://hg.openjdk.java.net/bsd-port/jdk8/hotspot/rev/062571963acf

. Fix compilation warning from change in _id type. Allows build
to complete with COMPILER_WARNINGS_FATAL=true.

! src/share/vm/utilities/vmError.cpp