Dealing with code style violations around the return keyword, I figured
I could automate that fix, so I tried with my favourite refactoring tool
and following those steps:

    $ cat >return.cocci <<EOF
    @@
    expression rv;
    @@

    - return rv;
    + return (rv);
    EOF
    $ spatch --dir . --in-place --sp-file return.cocci

Unfortunately that leads to proper return statements having their return
value enclosed twice, like `return ((rv))`. So a bit more steps to go:

    $ cat >rereturn.cocci <<EOF
    @@
    expression rv;
    @@

    - return ((rv));
    + return (rv);
    EOF
    $ spatch --dir . --in-place --sp-file rreeturn.cocci

At this point you don't want to touch bundled code, right? So let's take
care of libvgz and shout out to teken that saw no changes at all!

    $ git checkout -- lib/libvgz/

The next step is to manually review all the changes, because Coccinelle
is not aware of how we break lines and unbreaks them. That's quite
tedious but I was waiting for someone and they are still late as I'm
describing the whole process.

Care was taken not to touch varnishtest to make it easier to sync with
vtest. A dedicated patch will follow.