[jdk20] RFR: JDK-8298700: Typo in DocTree comment

[Jonathan Gibbons]

Please review a trivial fix to a long-standing copy-paste typo.

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Commit messages:
 - JDK-8298700: Typo in DocTree comment

Changes: https://git.openjdk.org/jdk20/pull/28/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20&pr=28&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298700
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk20/pull/28.diff
  Fetch: git fetch https://git.openjdk.org/jdk20 pull/28/head:pull/28

PR: https://git.openjdk.org/jdk20/pull/28