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/niu.c b/drivers/net/niu.c
index 2346ca6..c26325d 100644
--- a/drivers/net/niu.c
+++ b/drivers/net/niu.c
@@ -6447,11 +6447,11 @@
 
 	ipv6 = ihl = 0;
 	switch (skb->protocol) {
-	case __constant_htons(ETH_P_IP):
+	case cpu_to_be16(ETH_P_IP):
 		ip_proto = ip_hdr(skb)->protocol;
 		ihl = ip_hdr(skb)->ihl;
 		break;
-	case __constant_htons(ETH_P_IPV6):
+	case cpu_to_be16(ETH_P_IPV6):
 		ip_proto = ipv6_hdr(skb)->nexthdr;
 		ihl = (40 >> 2);
 		ipv6 = 1;