Depmod in the zfs makefiles will never run as `/boot/` and relevant map files dont exist in our build environments.
Included style suggestions by @rn
Signed-off-by: Matt Johnson <matjohn2@cisco.com>
Note this is not the latest ZFS version but the version matched
by the current alpine zfs utilities.
Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>