RFR: 8365671: Typo in Joiner.allUntil example

[Alan Bateman]

Fix two typos in one of the examples in Joiner.allUntil's API. (We may re-visit the example in a future update, for now, just the typos).

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/26856/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26856&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365671
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/26856.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26856/head:pull/26856

PR: https://git.openjdk.org/jdk/pull/26856