[jdk21] RFR: 8311593: Minor doc issue in MemorySegment::copy

[Maurizio Cimadamore]

Clean backport of https://git.openjdk.org/jdk/pull/14813
(sorry for filing another one, I realized there was an issue with the JBS issues pointing the wrong way)

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Commit messages:
 - Backport 6569b252b9e61e3eed77039c483529154feffbba

Changes: https://git.openjdk.org/jdk21/pull/109/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21&pr=109&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8311593
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21/pull/109.diff
  Fetch: git fetch https://git.openjdk.org/jdk21.git pull/109/head:pull/109

PR: https://git.openjdk.org/jdk21/pull/109