kbfs_cr_test: fix unembedded test on 386 platforms (#302)
kbfs_cr_test: fix unembedded test on 386 platforms (#302)

For some reason on 386 platforms, the CR revision is less than 256
bytes, but on x64 platforms it's more.  Handle both by dropping the
limit down to 128 bytes.

Issue: KBFS-1480
keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/kbfs,keybase/client,keybase/client,keybase/client