RFR: 8277316: ciReplay: dump_replay_data is not thread-safe

[Dean Long]

Using a static buffer for the file name causes corrupted replay files.  Fixed.

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Commit messages:
 - use stack buffer instead of static buffer

Changes: https://git.openjdk.java.net/jdk/pull/6426/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6426&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277316
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6426.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6426/head:pull/6426

PR: https://git.openjdk.java.net/jdk/pull/6426