Previously, those ioctls were defined as 'in' only, so rdata.byte and
rdata.word were never updated in the userland. The read data went only
to rbuf if it was provided. Thus, consumers were forced to always use it.
Now the ioctls are marked as in-out.
Compatibility handlers are provided for old ioctls.
PR: 213481
Reported by: Lewis Donzis <lew@perftech.com>
MFC after: 2 weeks
Relnotes: maybe
Differential Revision: https://reviews.freebsd.org/D8430
f43618f59f