[jdk17u-dev] RFR: 8313710: jcmd: typo in the documentation of JFR.start and JFR.dump

[Goetz Lindenmaier]

I backport this for parity with 17.0.15-oracle.

Trivial resolve. 21 has some additional documentation lines.

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Commit messages:
 - Backport 16d917a85f9311611a14a63f1e53afae970efc73

Changes: https://git.openjdk.org/jdk17u-dev/pull/3088/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3088&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313710
  Stats: 106 lines in 2 files changed: 0 ins; 0 del; 106 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3088.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3088/head:pull/3088

PR: https://git.openjdk.org/jdk17u-dev/pull/3088