Calgary IOMMU: break out of pci_find_device_reverse if dev not found

From: Muli Ben-Yehuda <muli@il.ibm.com>

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

---
 arch/x86_64/kernel/pci-calgary.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux/arch/x86_64/kernel/pci-calgary.c
===================================================================
--- linux.orig/arch/x86_64/kernel/pci-calgary.c
+++ linux/arch/x86_64/kernel/pci-calgary.c
@@ -844,6 +844,8 @@ error:
 		dev = pci_find_device_reverse(PCI_VENDOR_ID_IBM,
 					      PCI_DEVICE_ID_IBM_CALGARY,
 					      dev);
+		if (!dev)
+			break;
 		if (!translate_phb(dev)) {
 			pci_dev_put(dev);
 			continue;