docs: kernel-hacking: Remove inappropriate text

Remove inappropriate sexual (and ableist) text from the locking
documentation, aligning it with the kernel code-of-conduct. As the text
was unrelated to locking, this change streamlines the document and
improves readability.

Signed-off-by: Alyssa Rosenzweig <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Corbet <[e-mail]>

Documentation/kernel-hacking/locking.rst

···
 Locking in the Linux Kernel
 ===========================
 
-If I could give you one piece of advice: never sleep with anyone crazier
-than yourself. But if I had to give you advice on locking: **keep it
-simple**.
+If I could give you one piece of advice on locking: **keep it simple**.
 
 Be reluctant to introduce new locks.
-
-Strangely enough, this last one is the exact reverse of my advice when
-you **have** slept with someone crazier than yourself. And you should
-think about getting a big dog.
 
 Two Main Types of Kernel Locks: Spinlocks and Mutexes
 -----------------------------------------------------