stmmac: intel: Eliminate useless conditions and variables

There are useless conditions like

	func()
	{
		...
		int ret;
		...
		ret = foo();
		if (ret)
			return ret;

		return 0;
	}

which may be replaced with direct return statement, what we have done here.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -347,16 +347,11 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 static int ehl_common_data(struct pci_dev *pdev,
 			   struct plat_stmmacenet_data *plat)
 {
-	int ret;
-
 	plat->rx_queues_to_use = 8;
 	plat->tx_queues_to_use = 8;
 	plat->clk_ptp_rate = 200000000;
-	ret = intel_mgbe_common_data(pdev, plat);
-	if (ret)
-		return ret;
 
-	return 0;
+	return intel_mgbe_common_data(pdev, plat);
 }
 
 static int ehl_sgmii_data(struct pci_dev *pdev,
@@ -457,16 +452,11 @@ static struct stmmac_pci_info ehl_pse1_sgmii1g_pci_info = {
 static int tgl_common_data(struct pci_dev *pdev,
 			   struct plat_stmmacenet_data *plat)
 {
-	int ret;
-
 	plat->rx_queues_to_use = 6;
 	plat->tx_queues_to_use = 4;
 	plat->clk_ptp_rate = 200000000;
-	ret = intel_mgbe_common_data(pdev, plat);
-	if (ret)
-		return ret;
 
-	return 0;
+	return intel_mgbe_common_data(pdev, plat);
 }
 
 static int tgl_sgmii_data(struct pci_dev *pdev,