selftests: netfilter: Run nft_audit.sh in its own netns

selftests: netfilter: Run nft_audit.sh in its own netns

commit 2e2d9c7d4d37d74873583d7b0c94eac8b6869486 upstream.

Don't mess with the host's firewall ruleset. Since audit logging is not
per-netns, add an initial delay of a second so other selftests' netns
cleanups have a chance to finish.

Fixes: e8dbde59ca3f ("selftests: netfilter: Test nf_tables audit logging")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>