cmd/upspin: adjust test to catch previous bug in createsuffixeduser
cmd/upspin: adjust test to catch previous bug in createsuffixeduser

Change-Id: I7758156787818726721865f9c8ae2bdc596f1298
Reviewed-on: https://upspin-review.googlesource.com/14484
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

upspin/upspin,upspin/upspin