zfsd: fix unit tests after 89f4f91dbfdcabe65bc7476bc5f13dfb837870fe

Reported by: markj
MFC after: 1 week
MFC with: 89f4f91dbfdcabe65bc7476bc5f13dfb837870fe
Sponsored by: Axcient
Reviewed by: Alek Pinchuk <pinchuk.alek@gmail.com>
Differential Revision: https://reviews.freebsd.org/D44744