grpc/dirserver: logf bug fix
grpc/dirserver: logf bug fix

s/%q/%d/

Change-Id: I7296a68f07a66ce5c353bc5330fb1d3f8242a1e1
Reviewed-on: https://upspin-review.googlesource.com/6643
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@google.com>

upspin/upspin,upspin/upspin