alx: remove redundant D0 power state set

Pci_enable_device_mem() will set device power state to D0,
so it's no need to do it again in alx_probe().
Also remove redundant PM Cap find code, because pci core
has been saved the pci device pm cap value.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index 027398e..fc95b23 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -1188,7 +1188,7 @@
 	struct alx_priv *alx;
 	struct alx_hw *hw;
 	bool phy_configured;
-	int bars, pm_cap, err;
+	int bars, err;
 
 	err = pci_enable_device_mem(pdev);
 	if (err)
@@ -1225,18 +1225,13 @@
 	pci_enable_pcie_error_reporting(pdev);
 	pci_set_master(pdev);
 
-	pm_cap = pci_find_capability(pdev, PCI_CAP_ID_PM);
-	if (pm_cap == 0) {
+	if (!pdev->pm_cap) {
 		dev_err(&pdev->dev,
 			"Can't find power management capability, aborting\n");
 		err = -EIO;
 		goto out_pci_release;
 	}
 
-	err = pci_set_power_state(pdev, PCI_D0);
-	if (err)
-		goto out_pci_release;
-
 	netdev = alloc_etherdev(sizeof(*alx));
 	if (!netdev) {
 		err = -ENOMEM;