kngclick: remove more duplicated code

Even though we got our boilerplate down to the decorator level,
it is still duplicated twice exactly.  Just separate out the
duplicate functionality into a break-out function.

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>
kngclick: fix version bug

Somehow version stopped working once we moved it out of
the scripts/kernelng module.  Probably something to do
with fancy setup.py shit I don't understand.  Anyhow, no
problem, we have explicit version retrieval all wired
up from version.  I had grand ideas about eliminating
it but, oh well, I've learned enough new tricks for today.

Signed-off-by: Gregory M. Turner <gmt@be-evil.net>