RFR: JDK-8290975 Minor cleanup could be done in javax.security [v2]

[Mark Powers]

> https://bugs.openjdk.org/browse/JDK-8290975

Mark Powers has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - just one more thing
 - Merge
 - sean and brad comments
 - second iteration
 - first iteration

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Changes: https://git.openjdk.org/jdk/pull/9664/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9664&range=01
  Stats: 110 lines in 16 files changed: 8 ins; 24 del; 78 mod
  Patch: https://git.openjdk.org/jdk/pull/9664.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9664/head:pull/9664

PR: https://git.openjdk.org/jdk/pull/9664