net: dsa: sja1105: fix error return code in sja1105_cls_flower_add()

The return value 'rc' maybe overwrite to 0 in the flow_action_for_each
loop, the error code from the offload not support error handling will
not set. This commit fix it to return -EOPNOTSUPP.

Fixes: 6a56e199 ("flow_offload: reject configuration of packet-per-second policing in offload drivers")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_flower.c

@@ -317,14 +317,13 @@ int sja1105_cls_flower_add(struct dsa_switch *ds, int port,
 	if (rc)
 		return rc;
 
-	rc = -EOPNOTSUPP;
-
 	flow_action_for_each(i, act, &rule->action) {
 		switch (act->id) {
 		case FLOW_ACTION_POLICE:
 			if (act->police.rate_pkt_ps) {
 				NL_SET_ERR_MSG_MOD(extack,
 						   "QoS offload not support packets per second");
+				rc = -EOPNOTSUPP;
 				goto out;
 			}