RFR: 8345267: Fix memory leak in JVMCIEnv dtor

[Doug Simon]

The `ALLOW_C_FUNCTION` macro takes the identifier for the relevant C function, followed by a statement containing the use as additional (variadic) macro args. This PR fixes a use of this macro where the leading identifier arg was being omitted.

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Commit messages:
 - fix use of ALLOW_C_FUNCTION

Changes: https://git.openjdk.org/jdk/pull/22471/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22471&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8345267
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22471.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22471/head:pull/22471

PR: https://git.openjdk.org/jdk/pull/22471