[jdk17] RFR: 8269064: Dropped messages of AsyncLogWriter cause memleak

[Xin Liu]

This patch freed c-strs for the dropped messages. Those c-strs are allocated from os::strdup.

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Commit messages:
 - 8269064: Dropped messages of AsyncLogWriter cause memleak

Changes: https://git.openjdk.java.net/jdk17/pull/121/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=121&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8269064
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/121.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/121/head:pull/121

PR: https://git.openjdk.java.net/jdk17/pull/121