Fix the linter check.

The linter changed the usage and doesn't require the --file flag
anymore.

.gitlab-ci.yml

@@ -19,7 +19,7 @@ lint templates:
       for template in templates/*.yml
       do
         echo "Checking $template" >&2
-        gitlab-ci-linter --server "$CI_SERVER_URL" --filename "$template" || EXITCODE=1
+        gitlab-ci-linter --server "$CI_SERVER_URL" "$template" || EXITCODE=1
         echo
       done
       [ -z "${EXITCODE:-}" ]