iommu/vt-d: fix bug in handling multiple RMRRs for the same PCI device

Function dmar_iommu_notify_scope_dev() makes a wrong assumption that
there's one RMRR for each PCI device at most, which causes DMA failure
on some HP platforms. So enhance dmar_iommu_notify_scope_dev() to
handle multiple RMRRs for the same PCI device.

Fixbug: https://bugzilla.novell.com/show_bug.cgi?id=879482

Cc: <stable@vger.kernel.org> # 3.15
Reported-by: Tom Mingarelli <thomas.mingarelli@hp.com>
Tested-by: Linda Knippers <linda.knippers@hp.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

@@ -3816,14 +3816,11 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
 				((void *)rmrr) + rmrr->header.length,
 				rmrr->segment, rmrru->devices,
 				rmrru->devices_cnt);
-			if (ret > 0)
-				break;
-			else if(ret < 0)
+			if(ret < 0)
 				return ret;
 		} else if (info->event == BUS_NOTIFY_DEL_DEVICE) {
-			if (dmar_remove_dev_scope(info, rmrr->segment,
-				rmrru->devices, rmrru->devices_cnt))
-				break;
+			dmar_remove_dev_scope(info, rmrr->segment,
+				rmrru->devices, rmrru->devices_cnt);
 		}
 	}