Warning output compares files free to space.

In the output of the running container some of the output is misleading/confusing regarding the frees files and lower files bound.

https://gitlab.com/gitlab-org/gitlab-runner-docker-cleanup/blob/master/cleanup.go#L471

	if diskSpace.FilesFree < lowFreeSpace {
		logrus.Warningln("Freeing files count. The free file count is below the lower bound:", diskSpace.FilesFree,
			"trying to free up to:", freeFiles)
	}

Should be

	if diskSpace.FilesFree < lowFreeFiles {

Internal Zendesk: https://gitlab.zendesk.com/agent/tickets/89526