[PATCH] mm: remove zap_page_range and create zap_vma_pages

[Christoph Hellwig]

I would have split this into one patch that adds the new
zap_vma_pages helper, and one to remove zap_page_range to split the
separate changes.

But the overall result looks fine, so feel free to add:

Reviewed-by: Christoph Hellwig <hch at lst.de>

to this or the split patches.