net: dpaa: Fix dtsec check for PCS availability

We want to fail if the PCS is not available, not if it is available. Fix
this condition.

Fixes: 5d93cfcf ("net: dpaa: Convert to phylink")
Reported-by: Christian Zigotzky <info@xenosoft.de>
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fman/fman_dtsec.c

@@ -1430,7 +1430,7 @@ int dtsec_initialization(struct mac_device *mac_dev,
 	dtsec->dtsec_drv_param->tx_pad_crc = true;
 
 	phy_node = of_parse_phandle(mac_node, "tbi-handle", 0);
-	if (!phy_node || of_device_is_available(phy_node)) {
+	if (!phy_node || !of_device_is_available(phy_node)) {
 		of_node_put(phy_node);
 		err = -EINVAL;
 		dev_err_probe(mac_dev->dev, err,