[jdk8u-dev] RFR: 8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10

[Jonathan Dowland]

This is a backport of 8278951 to jdk8u-dev as part of the cgroups v2 backport initiative.

Dependent PRs are in use.

It was clean (modulo path shuffles). The use of `log_trace` needed adjusting for jdk8u-dev.

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Depends on: https://git.openjdk.org/jdk8u-dev/pull/136

Commit messages:
 - replace log_trace with tty->print_cr
 - 8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10

Changes: https://git.openjdk.org/jdk8u-dev/pull/155/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=155&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8278951
  Stats: 7 lines in 2 files changed: 4 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/155.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/155/head:pull/155

PR: https://git.openjdk.org/jdk8u-dev/pull/155