The KMOD name is "zfs" instead of "openzfs" when building in FreeBSD.
Define a ZFS_KMOD symbol as "zfs" when IN_BASE is defined, otherwise
"openzfs".
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10699