Again, more work to do here..

Remove prototype. It was wrong anyway.

More to do, but its a beginning.

if ki_users = 1, we don't do the wakeup, which seems wrong.

These copies already did a verify_area above.

- Remove unneeded breaks
- Fix double spin_unlock_irqrestore problem

Achieves the same result.  From Lenz Grimmer at Mysql AG

Plus with a little codeshuffling, we can do away with the
prototypes.

From Dave Richards (drichards@mahinetworks.com)

  "While diagnosing an MMX/FPU problem I found a minor problem in the
   code which diagnoses and generates signals for FPU exceptions.  On
   x86 Stack Fault Exception are a subclass of Invalid Operation.  Thus,
   the FPU status register will have both the SF and IF bits set when a
   stack fault occurs.  The code which turns FPU exceptions into signals
   was assuming IF would be clear".