amd-xgbe: Checkpatch fixes

This set of patches resolves some checks reported by the checkpatch
tool.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c

@@ -328,7 +328,7 @@ void xgbe_debugfs_init(struct xgbe_prv_data *pdata)
 
 	buf = kasprintf(GFP_KERNEL, "amd-xgbe-%s", pdata->netdev->name);
 	pdata->xgbe_debugfs = debugfs_create_dir(buf, NULL);
-	if (pdata->xgbe_debugfs == NULL) {
+	if (!pdata->xgbe_debugfs) {
 		netdev_err(pdata->netdev, "debugfs_create_dir failed\n");
 		return;
 	}

drivers/net/ethernet/amd/xgbe/xgbe-drv.c

@@ -692,7 +692,7 @@ static void xgbe_adjust_link(struct net_device *netdev)
 	struct phy_device *phydev = pdata->phydev;
 	int new_state = 0;
 
-	if (phydev == NULL)
+	if (!phydev)
 		return;
 
 	if (phydev->link) {

drivers/net/ethernet/amd/xgbe/xgbe-mdio.c

@@ -220,7 +220,7 @@ int xgbe_mdio_register(struct xgbe_prv_data *pdata)
 	}
 
 	mii = mdiobus_alloc();
-	if (mii == NULL) {
+	if (!mii) {
 		dev_err(pdata->dev, "mdiobus_alloc failed\n");
 		ret = -ENOMEM;
 		goto err_node_get;