RFR: 8293159: Use try-with-resources in X11FontManager.registerFontDir

[Andrey Turbanov]

Makes code easier to read.

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Commit messages:
 - [PATCH] Use try-with-resources in X11FontManager.registerFontDir

Changes: https://git.openjdk.org/jdk/pull/9879/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9879&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293159
  Stats: 164 lines in 1 file changed: 45 ins; 55 del; 64 mod
  Patch: https://git.openjdk.org/jdk/pull/9879.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9879/head:pull/9879

PR: https://git.openjdk.org/jdk/pull/9879