PCI: disable ASPM on pre-1.1 PCIe devices

Disable ASPM on pre-1.1 PCIe devices, as many of them don't implement it
correctly.

Tested-by: Jack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2036300..7098dfb 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1057,7 +1057,8 @@
 		}
 	}
 
-	if (bus->self)
+	/* only one slot has pcie device */
+	if (bus->self && nr)
 		pcie_aspm_init_link_state(bus->self);
 
 	return nr;