ebtables: use extrapositioned negation consistently

ebtables: use extrapositioned negation consistently

in the iptables universe, we enforce extrapositioned negation:

! -i foo

"-i ! foo" is not even supported anymore.

At least make sure that ebtables prints the former syntax everywhere as
well so we don't have a mix of both ways.
Parsing of --option ! 42 will still work for backwards compat reasons.

Signed-off-by: Florian Westphal <fw@strlen.de>