RFR: 8280024: Parallel: Remove unnecessary PSCardTable::resize_covered_region_by_end

[Albert Mingkun Yang]

Simple change of removing effectively dead code.

Test: tier1-6

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Commit messages:
 - resize_covered_region_by_end

Changes: https://git.openjdk.java.net/jdk/pull/7087/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7087&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8280024
  Stats: 267 lines in 2 files changed: 0 ins; 264 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7087.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7087/head:pull/7087

PR: https://git.openjdk.java.net/jdk/pull/7087