[OpenJDK 2D-Dev] RFR: 8263363: Minor cleanup of Lanai code - unused code removal and comments correction

[Ajit Ghaisas]

Refer JBS for 3 issues that this PR addresses.
In addition, I have corrected an erroneous free() call in the same method I was cleaning up.

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Commit messages:
 - 8263363 - cleanup

Changes: https://git.openjdk.java.net/jdk/pull/3357/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3357&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263363
  Stats: 21 lines in 3 files changed: 1 ins; 16 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3357.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3357/head:pull/3357

PR: https://git.openjdk.java.net/jdk/pull/3357