Patch: Change uint32 to uint32_t in vfs.h

[Richard Sharpe]

Hi folks,

I was extremely shocked to find that there are around 104 instances of
uint32 in our code.

Here is a patch that changes 17 of them to uint32_t.

If this sort of thing is welcome, I will fix the rest.

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)