test: fix test-cli-syntax assertions on windows

The test introduced in a5f91ab2
accidentally introduced failures on some windows builds. Update the
assertion that was causing the failures.

PR-URL: https://github.com/nodejs/node/pull/12212
Ref: https://github.com/nodejs/node/pull/11689


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>