Commit 379ca9c removed the check on aux devices to be block devices also
changing zfs_ioctl(hdl, ZFS_IOC_VDEV_ADD, ...) and
zfs_ioctl(hdl, ZFS_IOC_POOL_CREATE, ...) to never set ENOTBLK. This
change removes the dangling check for ENOTBLK that will never trigger.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reported-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Alex John <alex@stty.io>
Closes#10173