Further improve LFS integrity check performance
A number of ideas were discussed in https://gitlab.com/gitlab-org/gitlab-ce/issues/41141, e.g. https://gitlab.com/gitlab-org/gitlab-ce/issues/41141#note_51993113.
A number of ideas were discussed in https://gitlab.com/gitlab-org/gitlab-ce/issues/41141, e.g. https://gitlab.com/gitlab-org/gitlab-ce/issues/41141#note_51993113.