PCI: Delete unnecessary NULL pointer checks

The functions pci_dev_put(), pci_pme_wakeup_bus(), and put_device() return
immediately if their argument is NULL.  Thus the test before the call is
not needed.

Remove these unnecessary tests.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 116ca37..f01b26d 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -596,8 +596,7 @@
 	pcidev = pci_get_bus_and_slot(bus, devfn);
 	if (!pcidev || !pcidev->driver) {
 		dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
-		if (pcidev)
-			pci_dev_put(pcidev);
+		pci_dev_put(pcidev);
 		return result;
 	}
 	pdrv = pcidev->driver;