net: replace __constant_{endian} uses in net headers

Base versions handle constant folding now.  For headers exposed to
userspace, we must only expose the __ prefixed versions.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index 7040a78..9b5d08f 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -113,12 +113,12 @@
 static inline int INET_ECN_set_ce(struct sk_buff *skb)
 {
 	switch (skb->protocol) {
-	case __constant_htons(ETH_P_IP):
+	case cpu_to_be16(ETH_P_IP):
 		if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
 			return IP_ECN_set_ce(ip_hdr(skb));
 		break;
 
-	case __constant_htons(ETH_P_IPV6):
+	case cpu_to_be16(ETH_P_IPV6):
 		if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
 			return IP6_ECN_set_ce(ipv6_hdr(skb));
 		break;