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 <alyssa@rosenzweig.io>
Link: https://lore.kernel.org/r/20210903151826.6300-1-alyssa@rosenzweig.io


Signed-off-by: Jonathan Corbet <corbet@lwn.net>