netfilter: nf_tables: Open-code audit log call in nf_tables_getrule()

[ Upstream commit 88773930 ]

The table lookup will be dropped from that function, so remove that
dependency from audit logging code. Using whatever is in
nla[NFTA_RULE_TABLE] is sufficient as long as the previous rule info
filling succeded.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 9adbb419 ("netfilter: nf_tables: avoid false-positive lockdep splat on rule deletion")
Signed-off-by: Sasha Levin <sashal@kernel.org>