PCI: Do not run NVidia quirks related to MSI with MSI disabled

There is no reason to run NVidia-specific quirks related to HT MSI
mappings with MSI disabled via pci=nomsi, so make
__nv_msi_ht_cap_quirk() return immediately in that case.

This allows at least one machine to boot 100% of the time with
pci=nomsi (it still doesn't boot reliably without that).

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16443 .

Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/quirks.c

@@ -2421,6 +2421,9 @@ static void __devinit __nv_msi_ht_cap_quirk(struct pci_dev *dev, int all)
 	int pos;
 	int found;
 
+	if (!pci_msi_enabled())
+		return;
+
 	/* check if there is HT MSI cap or enabled on this device */
 	found = ht_check_msi_mapping(dev);