RFR: 8334758: Incorrect note in Javadoc for a few RandomGenerator methods

[Raffaello Giulietti]

Small corrections to @implSpec notes in a few methods in RandomGenerator.

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Commit messages:
 - 8334758: Incorrect note in Javadoc for a few RandomGenerator methods

Changes: https://git.openjdk.org/jdk/pull/20152/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20152&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334758
  Stats: 28 lines in 1 file changed: 0 ins; 5 del; 23 mod
  Patch: https://git.openjdk.org/jdk/pull/20152.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20152/head:pull/20152

PR: https://git.openjdk.org/jdk/pull/20152