We try to free two pages when only one has been allocated.
Cleanup path is unlikely, so I haven't found any trace that would fit,
but I hope that free_pages_prepare() does catch it.
Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Amos Kong <akong@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>