net: enetc: check the index of the SFI rather than the handle

We should check whether the current SFI (Stream Filter Instance) table
is full before creating a new SFI entry. However, the previous logic
checks the handle by mistake and might lead to unpredictable behavior.

Fixes: 888ae5a3 ("net: enetc: add tc flower psfp offload driver")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/enetc/enetc_qos.c

@@ -1247,7 +1247,7 @@ static int enetc_psfp_parse_clsflower(struct enetc_ndev_priv *priv,
 		int index;
 
 		index = enetc_get_free_index(priv);
-		if (sfi->handle < 0) {
+		if (index < 0) {
 			NL_SET_ERR_MSG_MOD(extack, "No Stream Filter resource!");
 			err = -ENOSPC;
 			goto free_fmi;