tlf_journal: use unflushedPathsCache
tlf_journal: use unflushedPathsCache

Suggested by @akalin-keybase

Issue: KBFS-1477
Issue: #422

keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client