KVM: mips: use id_to_memslot correctly

commit 69a12200 upstream.

The argument to KVM_GET_DIRTY_LOG is a memslot id; it may not match the
position in the memslots array, which is sorted by gfn.
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[ luis: backported to 3.16:
  - file rename: arch/mips/kvm/mips.c -> arch/mips/kvm/kvm_mips.c ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

arch/mips/kvm/kvm_mips.c

@@ -813,7 +813,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 
 	/* If nothing is dirty, don't bother messing with page tables. */
 	if (is_dirty) {
-		memslot = &kvm->memslots->memslots[log->slot];
+		memslot = id_to_memslot(kvm->memslots, log->slot);
 
 		ga = memslot->base_gfn << PAGE_SHIFT;
 		ga_end = ga + (memslot->npages << PAGE_SHIFT);