dma_alloc_coherent: clean it up

This thing was rather stupidly coded.  Rework it all prior to making
changes.

Also, rename local variable `page': kernel readers expect something called
`page' to have type `struct page *'.

Cc: Guennadi Liakhovetski <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Jesse Barnes <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed