RFR: 8263531: Remove unused buffer int

[Christoph Langer]

The change for JDK-8257001 left an obsolete int field. Remove it.

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Commit messages:
 - JDK-8263531

Changes: https://git.openjdk.java.net/jdk/pull/4759/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4759&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263531
  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4759.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4759/head:pull/4759

PR: https://git.openjdk.java.net/jdk/pull/4759