[jdk17u-dev] RFR: 8346908: Update JDK 17 javadoc man page

[Goetz Lindenmaier]

I backport this for parity with 17.0.15-oracle.

I "implemented" this based on the description.

Obviously the description ended up at the wrong flag.

test this by calling

man build/.../images/jdk/man/man1/javadoc.1

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Commit messages:
 - Backport 8346908: Update JDK 17 javadoc man page

Changes: https://git.openjdk.org/jdk17u-dev/pull/3243/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3243&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346908
  Stats: 12 lines in 1 file changed: 6 ins; 5 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3243.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3243/head:pull/3243

PR: https://git.openjdk.org/jdk17u-dev/pull/3243