[NETPOLL]: Another udp checksum mangling.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 8be3681..3c58846 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -296,7 +296,7 @@
 					udp_len, IPPROTO_UDP,
 					csum_partial((unsigned char *)udph, udp_len, 0));
 	if (udph->check == 0)
-		udph->check = -1;
+		udph->check = CSUM_MANGLED_0;
 
 	skb->nh.iph = iph = (struct iphdr *)skb_push(skb, sizeof(*iph));