ipv4: Simplify iph->daddr overwrite in ip_options_rcv_srr().

We already copy the 4-byte nexthop from the options block into
local variable "nexthop" for the route lookup.

Re-use that variable instead of memcpy()'ing again when assigning
to iph->daddr after the route lookup succeeds.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ip_options.c

@@ -635,7 +635,7 @@ int ip_options_rcv_srr(struct sk_buff *skb)
 		if (rt2->rt_type != RTN_LOCAL)
 			break;
 		/* Superfast 8) loopback forward */
-		memcpy(&iph->daddr, &optptr[srrptr-1], 4);
+		iph->daddr = nexthop;
 		opt->is_changed = 1;
 	}
 	if (srrptr <= srrspace) {