net: dsa: lan9303: Only allocate 3 ports

Save 2628 bytes on arm eabi by allocate only the required 3 ports.

Now that ds->num_ports is correct: In net/dsa/tag_lan9303.c
eliminate duplicate LAN9303_MAX_PORTS, use ds->num_ports.
(Matching the pattern of other net/dsa/tag_xxx.c files.)

Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/tag_lan9303.c

@@ -39,7 +39,6 @@
  */
 
 #define LAN9303_TAG_LEN 4
-#define LAN9303_MAX_PORTS 3
 
 static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev)
 {
@@ -104,7 +103,7 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
 
 	source_port = ntohs(lan9303_tag[1]) & 0x3;
 
-	if (source_port >= LAN9303_MAX_PORTS) {
+	if (source_port >= ds->num_ports) {
 		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
 		return NULL;
 	}