Replace insanely slow recorded timestamp repair function with a simple call to
the standard status walker which is already optimized for performance for
different reasons and already fixes recorded timestamps when the working copy
is locked.

This appears to be a regression on trunk which I accidentally found by
attaching a debugger to a 'svn cleanup' which was running for minutes.
(It is now done in a few seconds on the same case)

* subversion/libsvn_wc/cleanup.c
  (repair_timestamps): Remove function.
  (status_dummy_callback): New function.
  (cleanup_internal): Use status walker.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1633126 13f79535-47bb-0310-9956-ffa450edef68