journal_server_test: better reader TLF test name
journal_server_test: better reader TLF test name

Issue: KBFS-2643

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