The link for patch submission information in general refers to index
page for "Working with the kernel development community" section of
kernel docs, whereas the link should have been
Documentation/process/submitting-patches.rst instead.

Fix it by replacing the index target with the appropriate doc.

Fixes: 54222838 ("bpf, doc: convert bpf_devel_QA.rst to use RST formatting")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230228074523.11493-3-bagasdotme@gmail.com