pvfs_bufmap_copy_from_iovec(): don't rely upon size being equal to iov_iter_count(iter)

				int buffer_index,

				size_t size)

{

	struct pvfs_bufmap_desc *to;

	struct page *page;

	size_t copied;

	struct pvfs_bufmap_desc *to = &bufmap->desc_array[buffer_index];

	int i;

	gossip_debug(GOSSIP_BUFMAP_DEBUG,

		     "%s: buffer_index:%d: size:%lu:\n",

		     "%s: buffer_index:%d: size:%zu:\n",

		     __func__, buffer_index, size);

	to = &bufmap->desc_array[buffer_index];

	for (i = 0; size; i++) {

		page = to->page_array[i];

		copied = copy_page_from_iter(page, 0, PAGE_SIZE, iter);

		size -= copied;

		if ((copied == 0) && (size))

			break;

		struct page *page = to->page_array[i];

		size_t n = size;

		if (n > PAGE_SIZE)

			n = PAGE_SIZE;

		n = copy_page_from_iter(page, 0, n, iter);

		if (!n)

			return -EFAULT;

		size -= n;

	}

	return size ? -EFAULT : 0;

	return 0;

}