arch/powerpc/kvm/book3s: use vma_lookup() in kvmppc_hv_setup_htab_rma()

Using vma_lookup() removes the requirement to check if the address is
within the returned vma.  The code is easier to understand and more
compact.

Link: https://lkml.kernel.org/r/20210521174745.2219620-7-Liam.Howlett@Oracle.comSigned-off-by: NLiam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: NLaurent Dufour <ldufour@linux.ibm.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/kvm/book3s_hv.c

@@ -4758,8 +4758,8 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 	/* Look up the VMA for the start of this memory slot */
 	hva = memslot->userspace_addr;
 	mmap_read_lock(kvm->mm);
-	vma = find_vma(kvm->mm, hva);
-	if (!vma || vma->vm_start > hva || (vma->vm_flags & VM_IO))
+	vma = vma_lookup(kvm->mm, hva);
+	if (!vma || (vma->vm_flags & VM_IO))
 		goto up_out;
 
 	psize = vma_kernel_pagesize(vma);