ACPI Exception (video-1721): UNKNOWN_STATUS_CODE, Cant attach device

The child of a video bus device is not alway a video device.
It should be a warn message rather than an exception here.
http://bugzilla.kernel.org/show_bug.cgi?id=9761

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 5e5dda3a..d089c45 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1713,7 +1713,8 @@
 
 		status = acpi_video_bus_get_one_device(dev, video);
 		if (ACPI_FAILURE(status)) {
-			ACPI_EXCEPTION((AE_INFO, status, "Cant attach device"));
+			ACPI_DEBUG_PRINT((ACPI_DB_WARN,
+					"Cant attach device"));
 			continue;
 		}
 	}