kbfsgit: fix the "Entering stage" log message
kbfsgit: fix the "Entering stage" log message

The object count was printed wrong, and sometimes the stage desc can
be empty (e.g., for StatusDone).

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