RFR: 8298321: 2 File Leak defect groups in 2 files

[Calvin Cheung]

Please review this simple change for fixing two file leak warnings: 
1) DirectivesParser::parse_from_file_inner() in open/src/hotspot/share/compiler/directivesParser.cpp 
2) mmap_attach_shared() in open/src/hotspot/os/posix/perfMemory_posix.cpp

Please refer to the [comment](https://bugs.openjdk.org/browse/JDK-8298321?focusedCommentId=14549361&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14549361) in the bug report for details.

Passed tiers 1 and 2 testing.

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Commit messages:
 - 8298321: 2 File Leak defect groups in 2 files

Changes: https://git.openjdk.org/jdk/pull/11909/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11909&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298321
  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/11909.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11909/head:pull/11909

PR: https://git.openjdk.org/jdk/pull/11909