RFR: 8360548: Parallel: Remove outdated comments in MutableNUMASpace::bias_region

[Albert Mingkun Yang]

Trivial removing outdated comments.

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Commit messages:
 - trivial

Changes: https://git.openjdk.org/jdk/pull/25984/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25984&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360548
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/25984.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25984/head:pull/25984

PR: https://git.openjdk.org/jdk/pull/25984