Update the documentation for `@return` tag of `putIfAbsent` to match the main description. `putIfAbsent` uses the same wording as `put` for its `@return` tag, but that is incorrect. `putIfAbsent` never returns the **previous** value, as the whole point of the method is not the replace the value if it was present. As such, if it returns a value, it is the **current** value, and in all other cases it will return `null`.
------------- Commit messages: - Improve putIfAbsent documentation Changes: https://git.openjdk.org/jdk/pull/17438/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17438&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8323760 Stats: 4 lines in 1 file changed: 0 ins; 1 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/17438.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/17438/head:pull/17438 PR: https://git.openjdk.org/jdk/pull/17438
