Fix check-added-large-files --enforce-all to correctly consider all git-lfs files.

`git lfs status` only outputs status for files that are pending some git-lfs related operation.
For usage with --enforce-all, we need the list of all files that are tracked, which can be
achived by `git lfs ls-files`.

Fixes: https://github.com/pre-commit/pre-commit-hooks/issues/560