RFR: 8357999: SA: FileMapInfo.metadataTypeArray initialization issue after JDK-8355003

[Aleksey Shipilev]

SonarCloud reports an issue since [JDK-8355003](https://bugs.openjdk.org/browse/JDK-8355003) integration: duplicate index in `metadataTypeArray` initialization code. Looks like a simple typo, this PR fixes it. 

Additional testing:
 - [x] Linux x86_64 server fastdebug, `serviceability/sa`

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/25507/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25507&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357999
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/25507.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25507/head:pull/25507

PR: https://git.openjdk.org/jdk/pull/25507