RFR: 8265323: Leftover local variables in PcDesc

[Yi Yang]

Leftover local variables in PcDesc. Remove it to save electric power.

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Commit messages:
 - remove unused local vars

Changes: https://git.openjdk.java.net/jdk/pull/3532/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3532&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265323
  Stats: 6 lines in 1 file changed: 0 ins; 5 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3532.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3532/head:pull/3532

PR: https://git.openjdk.java.net/jdk/pull/3532