RFR: 8271268: Fix Javadoc links for Stream.mapMulti

[Mourad Abbay]

Fix Javadoc links for Stream.mapMulti, Stream.MapMultiInt, Stream.mapMultiToInt, Stream.mapMultiToLong and Stream.mapMultiToDouble.

-------------

Commit messages:
 - Fix Javadoc links for Stream.mapMulti.

Changes: https://git.openjdk.org/jdk/pull/15794/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15794&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8271268
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/15794.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15794/head:pull/15794

PR: https://git.openjdk.org/jdk/pull/15794