RFR: Revert unnecessary changes to unified logging

[William Kemper]

These are vestigial changes from the initial approach to support logging for the region sampling. This initial approach was abandoned and these changes should have been reverted at that time.

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Commit messages:
 - Revert unnecessary changes to unified logging

Changes: https://git.openjdk.org/shenandoah/pull/207/files
 Webrev: https://webrevs.openjdk.org/?repo=shenandoah&pr=207&range=00
  Stats: 28 lines in 2 files changed: 14 ins; 14 del; 0 mod
  Patch: https://git.openjdk.org/shenandoah/pull/207.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah pull/207/head:pull/207

PR: https://git.openjdk.org/shenandoah/pull/207