net: systemport: Fix sparse warnings in bcm_sysport_insert_tsb()

skb->protocol is a __be16 which we would be calling htons() against,
while this is not wrong per-se as it correctly results in swapping the
value on LE hosts, this still upsets sparse. Adopt a similar pattern to
what other drivers do and just assign ip_ver to skb->protocol, and then
use htons() against the different constants such that the compiler can
resolve the values at build time.

Fixes: 80105bef ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -1192,7 +1192,7 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
 	u32 csum_info;
 	u8 ip_proto;
 	u16 csum_start;
-	u16 ip_ver;
+	__be16 ip_ver;
 
 	/* Re-allocate SKB if needed */
 	if (unlikely(skb_headroom(skb) < sizeof(*tsb))) {
@@ -1211,12 +1211,12 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
 	memset(tsb, 0, sizeof(*tsb));
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		ip_ver = htons(skb->protocol);
+		ip_ver = skb->protocol;
 		switch (ip_ver) {
-		case ETH_P_IP:
+		case htons(ETH_P_IP):
 			ip_proto = ip_hdr(skb)->protocol;
 			break;
-		case ETH_P_IPV6:
+		case htons(ETH_P_IPV6):
 			ip_proto = ipv6_hdr(skb)->nexthdr;
 			break;
 		default:
@@ -1230,7 +1230,8 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
 
 		if (ip_proto == IPPROTO_TCP || ip_proto == IPPROTO_UDP) {
 			csum_info |= L4_LENGTH_VALID;
-			if (ip_proto == IPPROTO_UDP && ip_ver == ETH_P_IP)
+			if (ip_proto == IPPROTO_UDP &&
+			    ip_ver == htons(ETH_P_IP))
 				csum_info |= L4_UDP;
 		} else {
 			csum_info = 0;