RFR: JDK-8325470: [AIX] use fclose after fopen in read_psinfo

[Matthias Baesken]

There seems to be a missing fclose after fopen in read_psinfo (os_perf_aix.cpp).

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

Commit messages:
 - JDK-8325470

Changes: https://git.openjdk.org/jdk/pull/17769/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17769&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325470
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17769.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17769/head:pull/17769

PR: https://git.openjdk.org/jdk/pull/17769