[jdk21] RFR: 8310549: avoid potential leaks in KeystoreImpl.m related to JNU_CHECK_EXCEPTION early returns

[Matthias Baesken]

8310549: avoid potential leaks in KeystoreImpl.m related to JNU_CHECK_EXCEPTION early returns

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Commit messages:
 - Backport 7da3f1999fc5d1b9162443d97dfae7fe7b04dfc5

Changes: https://git.openjdk.org/jdk21/pull/86/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21&pr=86&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310549
  Stats: 6 lines in 1 file changed: 4 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21/pull/86.diff
  Fetch: git fetch https://git.openjdk.org/jdk21.git pull/86/head:pull/86

PR: https://git.openjdk.org/jdk21/pull/86