PCI/PM: Rearrange pci_update_current_state()

Save one config space access in pci_update_current_state() by testing the
retrieved PCI_PM_CTRL register value against PCI_POSSIBLE_ERROR() instead
of invoking pci_device_is_present() separately.

While at it, drop a pair of unnecessary parens.

No expected functional impact.

Link: https://lore.kernel.org/r/1917095.PYKUYFuaPT@kreacherSigned-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.c

@@ -1201,14 +1201,17 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
  */
 void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 {
-	if (platform_pci_get_power_state(dev) == PCI_D3cold ||
-	    !pci_device_is_present(dev)) {
+	if (platform_pci_get_power_state(dev) == PCI_D3cold) {
 		dev->current_state = PCI_D3cold;
 	} else if (dev->pm_cap) {
 		u16 pmcsr;
 
 		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
-		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+		if (PCI_POSSIBLE_ERROR(pmcsr)) {
+			dev->current_state = PCI_D3cold;
+			return;
+		}
+		dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
 	} else {
 		dev->current_state = state;
 	}