decruft the vmalloc API

[Christoph Hellwig]

On Wed, Apr 08, 2020 at 05:03:24PM +0100, Russell King - ARM Linux admin wrote:
> I haven't read all your patches yet.
> 
> Have you tested it on 32-bit ARM, where the module area is located
> _below_ PAGE_OFFSET and outside of the vmalloc area?

I have not tested it.  However existing in-kernel users that use
different areas (and we have quite a few of those) have not been
changed at all.  I think the arm32 module loader (like various other
module loaders) falls into that category.