RFR: 8376233: Clean up code in Desktop native peer

[Alexander Zuev]

Add corresponding memory release instructions into all the conditional return branches.

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Commit messages:
 - 8376233: Clean up code in Desktop native peer

Changes: https://git.openjdk.org/jdk/pull/29667/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29667&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376233
  Stats: 7 lines in 2 files changed: 5 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29667.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29667/head:pull/29667

PR: https://git.openjdk.org/jdk/pull/29667