status: mark --find-renames option with NONEG

status: mark --find-renames option with NONEG

If you run "git status --no-find-renames", it will behave the same as
"--find-renames", because we ignore the "unset" parameter (we see a NULL
"arg", but since the score argument is optional, we just think that the
user did not provide a score).

We already have a separate "--no-renames" to disable renames, so there's
not much point in supporting "--no-find-renames". Let's just flag it as
an error.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>