9213 zfs: sytem typo

illumos/illumos-gate@edc8ef7d921c96b23969898aeb766cb24960bda7

Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Approved by: Joshua M. Clulow <josh@sysmgr.org>
Author: Toomas Soome <tsoome@me.com>