RFR: 8333522: JFR SwapSpace event might read wrong free swap space size

[Matthias Baesken]

In some cgroups v2 based test system , a too large free swap space value has been observed.
The value should not be larger than total swap space.

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Commit messages:
 - JDK-8333522

Changes: https://git.openjdk.org/jdk/pull/19574/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19574&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333522
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/19574.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19574/head:pull/19574

PR: https://git.openjdk.org/jdk/pull/19574