cmd/dfuse: make logging output matchable to the bazil.org logging.
cmd/dfuse: make logging output matchable to the bazil.org logging.

Change-Id: I4971498fb1e758d837593cfd1d36a81fad1b5499
Reviewed-on: https://upspin-review.git.corp.google.com/1912
Reviewed-by: Eduardo Pinheiro <55040cbb39ba395339ae7940d8da6cd97797a4a8@google.com>

upspin/upspin,upspin/upspin