RFR: 8275375: jfr/api/consumer/security/TestStreamingRemote.java fails with AccessControlException

[Yasumasa Suenaga]

We can see AccessControlException in some JFR tests since [JDK-8271949](https://bugs.openjdk.java.net/browse/JDK-8271949). It is caused that SecurityException happens in both `File::canWrite` and `Path::toRealPath`. We should fall-through with empty path because the path will be evaluated when emergency dump happens.

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Commit messages:
 - 8275375: jfr/api/consumer/security/TestStreamingRemote.java fails with AccessControlException

Changes: https://git.openjdk.java.net/jdk/pull/5984/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5984&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275375
  Stats: 10 lines in 1 file changed: 4 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5984.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5984/head:pull/5984

PR: https://git.openjdk.java.net/jdk/pull/5984