docs: dev-tools: modify SPL reference URL to actual SPL doc entry

Fix the invalid url about Semantic Patch Language

Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220613071243.12961-1-dzm91@hust.edu.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
1 file changed