extensions: conntrack: Use the right callbacks

extensions: conntrack: Use the right callbacks

These version-agnostic conntrack match aliases emulating the 'state'
extension introduced by commit 0d70163162589 ("libxt_state: replace as
an alias to xt_conntrack") had incompatible print and save callbacks
assigned. These callbacks expected struct xt_state_info in match->data
which is incompatible to any of the actual xt_conntrack_mtinfo* structs
used.

Fixes: b28d4dcc9f555 ("iptables: state match incompatibilty across versions")
Signed-off-by: Phil Sutter <phil@nwl.cc>