RFR: jcheck: report all issues from "committer" check

[Erik Helin]

Hi all,

please review this patch that ensures that the "committer" check in JCheck
reports all issues at once instead of one at a time.

Testing:
- `make test` on Linux x64
- Updated two unit tests

Thanks,
Erik

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Commit messages:
 - jcheck: report all issues from "committer" check

Changes: https://git.openjdk.java.net/skara/pull/532/files
 Webrev: https://webrevs.openjdk.java.net/skara/532/webrev.00
  Stats: 16 lines in 2 files changed: 5 ins; 0 del; 11 mod
  Patch: https://git.openjdk.java.net/skara/pull/532.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/532/head:pull/532

PR: https://git.openjdk.java.net/skara/pull/532