Use uintptr_t instead of unsigned long for pointers.

[jhb]

Summary

The sense_ptr thing is quite broken. As near as I can tell,
the driver tries to copyout to a physical address rather than
whatever user address the sense buffer should be copied to.
It is not immediately obvious what user address the sense
buffer should be copied to.

[imp]

no comment on what it's doing, but the casting I think is good.