netfilter: nf_tables: fix register ordering

netfilter: nf_tables: fix register ordering

[ d209df3e7f7002d9099fdb0f6df0f972b4386a63 ]

[ We hit the trace described in commit message with the
kselftest/nft_trans_stress.sh. This patch diverges from the upstream one
since kernel 4.14 does not have following symbols:
nft_chain_filter_init, nf_tables_flowtable_notifier ]

We must register nfnetlink ops last, as that exposes nf_tables to
userspace.  Without this, we could theoretically get nfnetlink request
before net->nft state has been initialized.

Fixes: 99633ab29b213 ("netfilter: nf_tables: complete net namespace support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[apanyaki: backport to v4.14-stable]
Signed-off-by: Andrew Paniakin <apanyaki@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>