netfilter: kill redundant check code in which setting ip_summed value

If the returned csum value is 0, We has set ip_summed with
CHECKSUM_UNNECESSARY flag in __skb_checksum_complete_head().

So this patch kills the check and changes to return to upper
caller directly.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 1 insertions, 3 deletions

diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 07de855e217..acd1ea87ba5 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -212,9 +212,7 @@ static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
                 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
                                                skb->len - dataoff, 0);
                 skb->ip_summed = CHECKSUM_NONE;
-                csum = __skb_checksum_complete_head(skb, dataoff + len);
-                if (!csum)
-                        skb->ip_summed = CHECKSUM_UNNECESSARY;
+                return __skb_checksum_complete_head(skb, dataoff + len);
         }
         return csum;
 }