fsck does not work on ZFS ZVOL formatted as UFS2

[David Evans]

This does not work

zroot2 is a ZFS pool

zfs create -V 10g zroot2/volume
newfs /dev/zvol/zroot2/volume
fsck /dev/zvol/zroot2/volume

returns error- fsck: Could not determine filesystem type

dumpfs and tunefs work on the volume.

Perhaps I am doing something wrong, otherwise I
would submit this as a bug report.

9-CURRENT as of a few days ago, amd64