ipvs: do not disable bh for long time

We used a global BH disable in LOCAL_OUT hook.
Add _bh suffix to all places that need it and remove
the disabling from LOCAL_OUT and sync code.

Functions like ip_defrag need protection from
BH, so add it. As for nf_nat_mangle_tcp_packet, it needs
RCU lock.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/net/netfilter/ipvs/ip_vs_app.c b/net/netfilter/ipvs/ip_vs_app.c
index a956030..dfd7b65 100644
--- a/net/netfilter/ipvs/ip_vs_app.c
+++ b/net/netfilter/ipvs/ip_vs_app.c
@@ -352,14 +352,14 @@
 				 unsigned int flag, __u32 seq, int diff)
 {
 	/* spinlock is to keep updating cp->flags atomic */
-	spin_lock(&cp->lock);
+	spin_lock_bh(&cp->lock);
 	if (!(cp->flags & flag) || after(seq, vseq->init_seq)) {
 		vseq->previous_delta = vseq->delta;
 		vseq->delta += diff;
 		vseq->init_seq = seq;
 		cp->flags |= flag;
 	}
-	spin_unlock(&cp->lock);
+	spin_unlock_bh(&cp->lock);
 }
 
 static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb,