RFR: JDK-8293472: Cgroup: 'stomping of _mount_path' crash if manually mounted cg controller exist [v5]

[王超]

> Similar to [JDK-8253435](https://bugs.openjdk.org/browse/JDK-8253435), when setting the mount path of cgroup controller "memory/cpu/cpuacct/pids", it should also discard duplicate items.

王超 has updated the pull request incrementally with one additional commit since the last revision:

  Change warning to debug log

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10193/files
  - new: https://git.openjdk.org/jdk/pull/10193/files/3eed0907..338a0954

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10193&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10193&range=03-04

  Stats: 45 lines in 3 files changed: 25 ins; 5 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/10193.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10193/head:pull/10193

PR: https://git.openjdk.org/jdk/pull/10193