Following up on r1534295, it appears that renaming_history_repos is a helper
function that looked like a test. Rename and move it above its usages, and
add comment.

* subversion/tests/cmdline/log_tests.py
  (create_renaming_history_repos): Move here.
  (log_multiple_revs_spanning_rename): Update caller.
  (log_auto_move): Update caller.
  (renaming_history_repos): Remove here.
  (test_list): Remove helper function as separate test.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1534299 13f79535-47bb-0310-9956-ffa450edef68