RFR: 8333714: Cleanup the usages of CHECK_EXCEPTION_NULL_FAIL macro in java launcher

[Jaikiran Pai]

Can I please get a review for this change which proposes to remove the `CHECK_EXCEPTION_NULL_FAIL` macro from the `java` launcher code?

This addresses https://bugs.openjdk.org/browse/JDK-8333714. As noted in that JBS issue, in a recent PR discussion, it was suggested https://github.com/openjdk/jdk/pull/18786#issuecomment-2147452633 that this macro should be removed and the failure of a JNI specified operation (the ones for which this macro is being used) should be determined based on a `NULL` value returned from that function. The commit in this PR removes this macros and updates the call sites to do a `NULL` check.

Given the nature of this change, no new tests have been added. tier1, tier2 and tier3 testing passed successfully with these changes.

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Commit messages:
 - simplify function comments
 - 8333714: Cleanup the usages of CHECK_EXCEPTION_NULL_FAIL macro in java launcher

Changes: https://git.openjdk.org/jdk/pull/19576/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19576&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333714
  Stats: 76 lines in 1 file changed: 45 ins; 9 del; 22 mod
  Patch: https://git.openjdk.org/jdk/pull/19576.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19576/head:pull/19576

PR: https://git.openjdk.org/jdk/pull/19576