netfilter: xt_connlimit: fix regression caused by zero family value

Commit v2.6.28-rc1~717^2~109^2~2 was slightly incomplete; not all
instances of par->match->family were changed to par->family.

References: http://bugzilla.netfilter.org/show_bug.cgi?id=610
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>