netfilter: nf_conntrack: remove an atomic bit operation

As this ct won't be seen by the others, we don't need to set the
IPS_CONFIRMED_BIT in atomic way.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/nf_conntrack_core.c

@@ -486,7 +486,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	ct->timeout.expires += jiffies;
 	add_timer(&ct->timeout);
 	atomic_inc(&ct->ct_general.use);
-	set_bit(IPS_CONFIRMED_BIT, &ct->status);
+	ct->status |= IPS_CONFIRMED;
 
 	/* Since the lookup is lockless, hash insertion must be done after
 	 * starting the timer and setting the CONFIRMED bit. The RCU barriers