Sigh...  First of all, LSI folks have very quaint idea of existing
platforms and word sizes on those.  Their definitions of U32 and S32
should really be reserved for posterity (preferably chiseled into the
rock they have between the ears), but kernel is the wrong place for
that.  Fixed.

mptctl_do_mpt_command() was always called on userland pointers;
kernel/userland argument removed along with dead code, function
annotated, callers updated.

The rest is trivial annotations in mptctl.c and in its ioctl structures
- nothing fancy there.