fs: remove the HAVE_UNLOCKED_IOCTL and HAVE_COMPAT_IOCTL defines

These are not defined anywhere, and contrary to the comments we really
do not care about out of tree code at all.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>