net: dsa: microchip: ksz9477: flower: validate control flags

Add check for unsupported control flags.

Only compile-tested, no access to HW.
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/ksz9477_tc_flower.c

@@ -124,6 +124,9 @@ static int ksz9477_flower_parse_key(struct ksz_device *dev, int port,
 		return -EOPNOTSUPP;
 	}
 
+	if (flow_rule_match_has_control_flags(rule, extack))
+		return -EOPNOTSUPP;
+
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC) ||
 	    flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 		ret = ksz9477_flower_parse_key_l2(dev, port, extack, rule,