Revert "mm: collect LRU list heads into struct lruvec from https://github.com/faux123/tuna/commit/80193636cf1f02380b5306c8b74de7b113c405d8"

This reverts commit c2c8a91ffbe75ea367a1f08270b1e4604208e53f.
Revert "mm: add free_hot_cold_page_list() helper from https://github.com/faux123/tuna/commit/30421791a40d9bd87a3780e48d3ef63cb82d8642"

This reverts commit 31a2b7d6647c33ad9065ced30948e88baa7342a1.