selftests: kselftest_harness.h: partially fix kernel-doc markups

The kernel-doc markups on this file are weird: they don't
follow what's specified at:

	Documentation/doc-guide/kernel-doc.rst

In particular, markups should use this format:
        identifier - description

and not this:
	identifier(args)

The way the definitions are inside this file cause the
parser to completely miss the identifier name of each
function.

This prevents improving the script to do some needed validation
tests.

Address this part. Yet, furter changes are needed in order
for it to fully follow the specs.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/8383758160fdb4fcbb2ac56beeb874ca6dffc6b9.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>