RFR: JDK-8284112 Minor cleanup could be done in javax.crypto

[Mark Powers]

JDK-8284112 Minor cleanup could be done in javax.crypto

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Commit messages:
 - second iteration
 - Merge
 - first iteration

Changes: https://git.openjdk.java.net/jdk/pull/8214/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8214&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284112
  Stats: 300 lines in 37 files changed: 9 ins; 79 del; 212 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8214.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8214/head:pull/8214

PR: https://git.openjdk.java.net/jdk/pull/8214