RFR: 8183336: Better cleanup for jdk/test/java/lang/module/customfs/ModulesInCustomFileSystem.java

[Arno Zeller]

We can set the java.io.tmpdir to point to the current directory to avoid polluting the temp directory.
@AlanBateman Thanks for this suggestion.

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

Commit messages:
 - Avoid creating mlibxxx directories in /tmp

Changes: https://git.openjdk.org/jdk/pull/27821/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27821&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8183336
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27821.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27821/head:pull/27821

PR: https://git.openjdk.org/jdk/pull/27821