netfilter: nf_tables: remove rcu read-size lock

Chain stats are updated from the Netfilter hook path which already run
under rcu read-size lock section.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_core.c

@@ -110,7 +110,6 @@ static noinline void nft_update_chain_stats(const struct nft_chain *chain,
 
 	base_chain = nft_base_chain(chain);
 
-	rcu_read_lock();
 	pstats = READ_ONCE(base_chain->stats);
 	if (pstats) {
 		local_bh_disable();
@@ -121,7 +120,6 @@ static noinline void nft_update_chain_stats(const struct nft_chain *chain,
 		u64_stats_update_end(&stats->syncp);
 		local_bh_enable();
 	}
-	rcu_read_unlock();
 }
 
 struct nft_jumpstack {