PCI: Reverse standard ACS vs device-specific ACS enabling

The original thought was that if a device implemented ACS, then surely
we want to use that... well, it turns out that devices can make an ACS
capability so broken that we still need to fall back to quirks.

Reverse the order of ACS enabling to give quirks first shot at it.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 25e0327..c98c4e2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2547,7 +2547,7 @@
  * pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
  * @dev: the PCI device
  */
-static int pci_std_enable_acs(struct pci_dev *dev)
+static void pci_std_enable_acs(struct pci_dev *dev)
 {
 	int pos;
 	u16 cap;
@@ -2555,7 +2555,7 @@
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
 	if (!pos)
-		return -ENODEV;
+		return;
 
 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
@@ -2573,8 +2573,6 @@
 	ctrl |= (cap & PCI_ACS_UF);
 
 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
-
-	return 0;
 }
 
 /**
@@ -2586,10 +2584,10 @@
 	if (!pci_acs_enable)
 		return;
 
-	if (!pci_std_enable_acs(dev))
+	if (!pci_dev_specific_enable_acs(dev))
 		return;
 
-	pci_dev_specific_enable_acs(dev);
+	pci_std_enable_acs(dev);
 }
 
 static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)