RFR: 8333046: Clean codes in sun.security.util.math

[John Jiang]

A simple cleanup on the changes introduced by JDK-8329538.

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Commit messages:
 - 8333046: Clean codes in sun.security.util.math

Changes: https://git.openjdk.org/jdk/pull/19429/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19429&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333046
  Stats: 9 lines in 6 files changed: 0 ins; 3 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/19429.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19429/head:pull/19429

PR: https://git.openjdk.org/jdk/pull/19429