CVE-2026-68168 afs: Fix afs_edit_dir_remove() to get, not find, block 0

In the Linux kernel, the following vulnerability has been resolved: afs: Fix afseditdirremove to get, not find, block 0 Fix afseditdirremove to use afsdirgetblock to get block 0 rather than afsdirfindblock as the latter caches the found block in the afsdiriter and may switch out the page it's on ...