folder_branch_ops: sigh, return err on err
folder_branch_ops: sigh, return err on err

Issue: KBFS-720

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