Needing kvm_pfn_page_unwrap is a sign that something might be buggy, so
it's a good idea to move the short name to the common case and the ugly
kvm_pfn_page_unwrap(gfn_to_pfn(...)) for the weird one. In fact I'm not
sure there should be any kvm_pfn_page_unwrap in the end.
If all callers were updated that is one thing, but from the changelog
it sounds like that would not happen and there would be some gfn_to_pfn
users left over.
But yes in the end you would either need to make gfn_to_pfn never return
a page found via follow_pte, or change all callers to the new way. If
the plan is for the latter then I guess that's fine.