virtio_balloon: divide/multiply instead of shifts

/* The size of a free page block in bytes */

#define VIRTIO_BALLOON_HINT_BLOCK_BYTES \

	(1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT))

#define VIRTIO_BALLOON_HINT_BLOCK_PAGES (1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER)

#ifdef CONFIG_BALLOON_COMPACTION

static struct vfsmount *balloon_mnt;

	unsigned long blocks_to_free, blocks_freed;

	pages_to_free = round_up(pages_to_free,

				 1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER);

	blocks_to_free = pages_to_free >> VIRTIO_BALLOON_HINT_BLOCK_ORDER;

				 VIRTIO_BALLOON_HINT_BLOCK_PAGES);

	blocks_to_free = pages_to_free / VIRTIO_BALLOON_HINT_BLOCK_PAGES;

	blocks_freed = return_free_pages_to_mm(vb, blocks_to_free);

	return blocks_freed << VIRTIO_BALLOON_HINT_BLOCK_ORDER;

	return blocks_freed * VIRTIO_BALLOON_HINT_BLOCK_PAGES;

}

static unsigned long leak_balloon_pages(struct virtio_balloon *vb,

	unsigned long count;

	count = vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE;

	count += vb->num_free_page_blocks << VIRTIO_BALLOON_HINT_BLOCK_ORDER;

	count += vb->num_free_page_blocks * VIRTIO_BALLOON_HINT_BLOCK_PAGES;

	return count;

}