[code-reflection] RFR: Fix javadoc issues

[Maurizio Cimadamore]

This simple PR fixes some issues preventing `make docs` to complete normally.

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Commit messages:
 - Initial push

Changes: https://git.openjdk.org/babylon/pull/715/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=715&range=00
  Stats: 10 lines in 4 files changed: 2 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/babylon/pull/715.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/715/head:pull/715

PR: https://git.openjdk.org/babylon/pull/715