arm64/mm: fix incorrect filemapcount for invalid pmd
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v6.1.7 by commit 21e5eca0ac9046da9918a919bc92b7b5a78d27e7, it was introduced in version v5.19 by commit 42b2547137f5c974bb1bfd657c869fe96b96d86f. For more details please see the references link.