tests: tempdirs with restrictive permissions are cleaned correctly Before this change, the removal of a temporary test directory containing subdirectories with restrictive permissions (such as 'r--r--r--') could fail. * tests/defs: Ensure that all the subdirectories of a temporary test directory have the 'read', 'write' and 'execute' bits set, before trying to remove it with `rm -rf'. * tests/Makefile.am (clean-local-check): Likewise.