vfio: use vma_lookup() instead of find_vma_intersection()

vma_lookup() finds the vma of a specific address with a cleaner interface
and is more readable.

Link: https://lkml.kernel.org/r/20210521174745.2219620-12-Liam.Howlett@Oracle.comSigned-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/vfio/vfio_iommu_type1.c

@@ -567,7 +567,7 @@ static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
 	vaddr = untagged_addr(vaddr);
 
 retry:
-	vma = find_vma_intersection(mm, vaddr, vaddr + 1);
+	vma = vma_lookup(mm, vaddr);
 
 	if (vma && vma->vm_flags & VM_PFNMAP) {
 		ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);