RFR: 8282763: G1: G1CardSetContainer remove intrusive-list details.

[Ivan Walulya]

Hi all,

Please review this trivial cleanup to remove unnecessary G1CardSetContainer list details.

Testing: tier 1

-------------

Commit messages:
 - space
 - initial

Changes: https://git.openjdk.java.net/jdk/pull/7743/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7743&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282763
  Stats: 27 lines in 1 file changed: 2 ins; 22 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7743.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7743/head:pull/7743

PR: https://git.openjdk.java.net/jdk/pull/7743