nfp_ct_merge_check
err = nfp_ct_merge_check(pre_ct_entry, nft_entry);
err = nfp_ct_merge_check(nft_entry, post_ct_entry);
err = nfp_ct_merge_check(pre_ct_entry, post_ct_entry);
return nfp_ct_merge_check(prev_nft_m_entry->nft_parent, nft_entry);