tests: Fix skipping mkdir-with-parents-permission test
tests: Fix skipping mkdir-with-parents-permission test

If the user has `CAP_DAC_OVERRIDE` or similar (for example, if running
the tests as root), the `mkdir-with-parents-permission` test is skipped.

The check for `CAP_DAC_OVERRIDE` was by creating a subdirectory of the
test directory. That subdirectory, however, was never removed, which
caused a ‘directory not empty’ error when trying to delete the test
directory.

Fix that by correctly deleting the subdirectory if skipping the test.

Signed-off-by: Philip Withnall <29c2a2ac2a854b9cf047275aa9de346d096be2e0@endlessm.com>

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib