net: dsa: tag_qca: use the generic flow dissector procedure

Remove the .flow_dissect procedure, so the flow dissector will call the
generic variant which works for this tagging protocol.

Cc: John Crispin <john@phrozen.org>
Cc: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/tag_qca.c

@@ -89,19 +89,11 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	return skb;
 }
 
-static void qca_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
-				 int *offset)
-{
-	*offset = QCA_HDR_LEN;
-	*proto = ((__be16 *)skb->data)[0];
-}
-
 static const struct dsa_device_ops qca_netdev_ops = {
 	.name	= "qca",
 	.proto	= DSA_TAG_PROTO_QCA,
 	.xmit	= qca_tag_xmit,
 	.rcv	= qca_tag_rcv,
-	.flow_dissect = qca_tag_flow_dissect,
 	.overhead = QCA_HDR_LEN,
 };