RFR: JDK-8267574: Dead code in HtmlStyle/HtmlDocletWriter

[Jonathan Gibbons]

Please review a simple `noreg-cleanup` change to remove some dead code.

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Commit messages:
 - JDK-8267574: Dead code in HtmlStyle/HtmlDocletWriter

Changes: https://git.openjdk.java.net/jdk/pull/4154/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4154&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267574
  Stats: 11 lines in 3 files changed: 0 ins; 9 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4154.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4154/head:pull/4154

PR: https://git.openjdk.java.net/jdk/pull/4154