net: sched: allow act_ct to be built without NF_NAT

In commit f11fe1da ("net/sched: Make NET_ACT_CT depends on NF_NAT"),
it fixed the build failure when NF_NAT is m and NET_ACT_CT is y by
adding depends on NF_NAT for NET_ACT_CT. However, it would also cause
NET_ACT_CT cannot be built without NF_NAT, which is not expected. This
patch fixes it by changing to use "(!NF_NAT || NF_NAT)" as the depend.

Fixes: f11fe1da ("net/sched: Make NET_ACT_CT depends on NF_NAT")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/b6386f28d1ba34721795fb776a91cbdabb203447.1668807183.git.lucien.xin@gmail.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>