re: kern/55782: INET/INET6 only semi-optional

[matthew green <mrg%eterna.com.au@localhost>]

FWIW, plain INET6-less is ok.  as a consumer of this, i've
helped keep it working.  i don't personally care about this
case (no inet at all), but i support it working.

> 	and a disturbing number of warnings elsewhere (mostly "this
> 	statement may fall through", to which my reaction is "if NetBSD
> 	cares about this, why hasn't it been fixed? if not, why is the
> 	warning turned on?" - but those in general do not look related
> 	to the INET/INET6 removal).

these warnings are in 3rd party code we don't want to modify
just to avoid a useless warning message.

if they come up as "warning" not "error", that means we have
explicitly chosen to ignore this verbosely.

the warning-as-error in general is useful, but not for this
specific case.  some we flat out disable or don't use.