net: rps: fix the wrong network header pointer

__skb_get_rxhash() was broken after the commit:

 commit bfb564e7391340638afe4ad67744a8f3858e7566
 Author: Krishna Kumar <krkumar2@in.ibm.com>
 Date:   Wed Aug 4 06:15:52 2010 +0000

 core: Factor out flow calculation from get_rps_cpu

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2283,7 +2283,7 @@ __u32 __skb_get_rxhash(struct sk_buff *skb)
 		if (!pskb_may_pull(skb, sizeof(*ip) + nhoff))
 			goto done;
 
-		ip = (struct iphdr *) skb->data + nhoff;
+		ip = (struct iphdr *) (skb->data + nhoff);
 		if (ip->frag_off & htons(IP_MF | IP_OFFSET))
 			ip_proto = 0;
 		else
@@ -2296,7 +2296,7 @@ __u32 __skb_get_rxhash(struct sk_buff *skb)
 		if (!pskb_may_pull(skb, sizeof(*ip6) + nhoff))
 			goto done;
 
-		ip6 = (struct ipv6hdr *) skb->data + nhoff;
+		ip6 = (struct ipv6hdr *) (skb->data + nhoff);
 		ip_proto = ip6->nexthdr;
 		addr1 = (__force u32) ip6->saddr.s6_addr32[3];
 		addr2 = (__force u32) ip6->daddr.s6_addr32[3];