FreeBSD: rework asserts in zfs_dd_lookup
- even up ifdefs
- drop the arguably useless teardown lock asserts -- nothing else checks for it
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11153