For the sake of developers who have LSP configured to auto-format the
code upon save (that would me with my new nvim setup), let's not
autoformat the C code when using clangd.
Initially I tried to write a set of rules for clang-format which is
identical to what we use (indent with a handful of options invoked
from cfmt target in Makefile), but it appears to be impossible.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>