netfilter: ipvs: fix incorrect conflict resolution

The commit ab8bc7ed
("netfilter: remove nf_ct_is_untracked")
changed the line
   if (ct && !nf_ct_is_untracked(ct) && nfct_nat(ct)) {
	   to
   if (ct && nfct_nat(ct)) {

meanwhile, the commit 41390895
("netfilter: ipvs: don't check for presence of nat extension")
from ipvs-next had changed the same line to

  if (ct && !nf_ct_is_untracked(ct) && (ct->status & IPS_NAT_MASK)) {

When ipvs-next got merged into nf-next, the merge resolution took
the first version, dropping the conversion of nfct_nat().

While this doesn't cause a problem at the moment, it will once we stop
adding the nat extension by default.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>