Get USE_STRICT_MM_TYPECHECKS working again

[Christoph Hellwig]

On Tue, Sep 09, 2008 at 03:04:47PM +1000, David Gibson wrote:
> The typesafe version of the powerpc pagetable handling (with
> USE_STRICT_MM_TYPECHECKS defined) has bitrotted again.  This patch
> makes a bunch of small fixes to get it building again.

It might be a better idea to mark these types __bitwise and use sparse
to do the stricter checking..