RFR: 8281149: (fs) java/nio/file/FileStore/Basic.java fails with java.langRuntimeException: values differ by more than 1GB

[Brian Burkhalter]

Modify the disk space verification to retrieve the expected value dynamically as the first parameter of the check method, as is done for the value being tested.

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Commit messages:
 - 8281149: (fs) java/nio/file/FileStore/Basic.java fails with java.lang.RuntimeException: values differ by more than 1GB

Changes: https://git.openjdk.org/jdk/pull/13480/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13480&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8281149
  Stats: 17 lines in 1 file changed: 4 ins; 3 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/13480.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13480/head:pull/13480

PR: https://git.openjdk.org/jdk/pull/13480