net: replace uses of __constant_{endian}

Base versions handle constant folding now.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index e9bcbdf..457f2d7 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -543,7 +543,7 @@
 /* Get packet from user space buffer */
 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 {
-	struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
+	struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 	struct sk_buff *skb;
 	size_t len = count, align = 0;
 	struct virtio_net_hdr gso = { 0 };