Fix the C tests to not remove test directories in --cleanup mode if the test failed.
Fix the C tests to not remove test directories in --cleanup mode if the
test failed.

* subversion/tests/svn_tests_main.c (skip_cleanup): New variable.
(cleanup_rmtree): Do nothing if skip_cleanup is non-zero.
(main): Propagate test error state to skip_cleanup.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion