Description of problem:
When scanning docker images and containers using oscap-docker tool, it exits with error and prints traceback.


Version-Release number of selected component (if applicable):
openscap-containers-1.2.15-1.fc26.noarch
openscap-1.2.15-1.fc26.x86_64


How reproducible:
100%


Steps to Reproduce:
$ sudo oscap-docker image fedora xccdf eval --profile standard /usr/share/xml/scap/ssg/content/ssg-fedora-ds.xml
W: probe_environmentvariable58: Requested offline mode is not supported by probe_environmentvariable58.
W: oscap:     There was a problem processing referenced variable (oval:ssg-var_accounts_root_path_dirs_no_write:v

Title   gpgcheck Enabled In Main Dnf Configuration
Rule    xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated
Result  pass

...

Title   Ensure that Root's Path Does Not Include World or Group-Writable Directories
Rule    xccdf_org.ssgproject.content_rule_accounts_root_path_dirs_no_write
Result  pass

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/docker/api/client.py", line 220, in _raise_for_status
    response.raise_for_status()
  File "/usr/lib/python3.6/site-packages/requests/models.py", line 909, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 404 Client Error: Not Found for url: http+docker://localunixsocket/v1.26/containers/tmpq1h_b657?v=False&link=False&force=False

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/bin/oscap-docker", line 117, in <module>
    args.func()
  File "/bin/oscap-docker", line 51, in scan
    result = OS.scan(self.args.scan_target, self.unknown_args)
  File "/usr/lib/python3.6/site-packages/oscap_docker_python/oscap_docker_util.py", line 276, in scan
    self.helper._cleanup_by_path(_tmp_mnt_dir)
  File "/usr/lib/python3.6/site-packages/oscap_docker_python/oscap_docker_util.py", line 177, in _cleanup_by_path
    DM._clean_temp_container_by_path(_no_rootfs)
  File "/usr/lib/python3.6/site-packages/Atomic/mount.py", line 742, in _clean_temp_container_by_path
    self.d.remove_container(short_cid)
  File "/usr/lib/python3.6/site-packages/Atomic/client.py", line 66, in newfunc
    result = attr(*args, **kwargs)
  File "/usr/lib/python3.6/site-packages/docker/utils/decorators.py", line 19, in wrapped
    return f(self, resource_id, *args, **kwargs)
  File "/usr/lib/python3.6/site-packages/docker/api/container.py", line 982, in remove_container
    self._raise_for_status(res)
  File "/usr/lib/python3.6/site-packages/docker/api/client.py", line 222, in _raise_for_status
    raise create_api_error_from_http_exception(e)
  File "/usr/lib/python3.6/site-packages/docker/errors.py", line 31, in create_api_error_from_http_exception
    raise cls(e, response=response, explanation=explanation)
docker.errors.NotFound: 404 Client Error: Not Found ("No such container: tmpq1h_b657")


Actual results:
oscap-docker prints traceback and exits with error.

Expected results:
oscap-docker does not traceback and finishes scan successfully.