PCI PM: Return error codes from pci_pm_resume()

Currently pci_pm_resume() always returns 0, which makes the error
variable defined in there a bit pointless.  Make pci_pm_resume()
return error codes obtained from drivers' callbacks.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/pci-driver.c

@@ -722,7 +722,7 @@ static int pci_pm_resume(struct device *dev)
 		pci_pm_reenable_device(pci_dev);
 	}
 
-	return 0;
+	return error;
 }
 
 #else /* !CONFIG_SUSPEND */