[jdk8u-dev] RFR: 8253435: Cgroup: 'stomping of _mount_path' crash if manually mounted cpusets exist

[Jonathan Dowland]

This is a clean backport of 8253435 to jdk8u-dev for cgroups v2 support.

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Depends on: https://git.openjdk.org/jdk8u-dev/pull/157

Commit messages:
 - 8253435: Cgroup: 'stomping of _mount_path' crash if manually mounted cpusets exist

Changes: https://git.openjdk.org/jdk8u-dev/pull/158/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=158&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8253435
  Stats: 40 lines in 2 files changed: 37 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/158.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/158/head:pull/158

PR: https://git.openjdk.org/jdk8u-dev/pull/158