docs: drop stale xdk-db reference

Author: 2045castor

pocs/linux/kernelctf/CVE-2026-43074_lts/docs/exploit.md

@@ -1,8 +1,6 @@
 # Exploit details for CVE-2026-43074
 
 If you need the bug background first, read [vulnerability.md](./vulnerability.md).
-If you need the kernelXDK DB additions and regeneration workflow, read [xdk-db.md](./xdk-db.md).
-
 ## Overview
 
 This exploit is a data-only privilege-escalation chain for the eventpoll use-after-free in CVE-2026-43074 ("epollution"). It does **not** try to get direct RIP control. Instead, it reuses the freed `struct eventpoll` object to steer `ep_get_upwards_depth_proc()` into controlled memory, uses repeated oopses as an information leak, and then uses the resulting write primitive to clear credential fields until one of the forked helper processes becomes root.