uas: fix error handling during scsi_scan()

intfdata is set only after scsi_scan(). uas_pre_reset() however
needs intfdata to be valid and will follow the NULL pointer
killing khubd. intfdata must be preemptively set before the
host is registered and undone in the error case.
Signed-off-by: NOliver Neukum <oliver@neukum.org>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/storage/uas.c

@@ -1096,16 +1096,17 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	if (result)
 		goto free_streams;
 
+	usb_set_intfdata(intf, shost);
 	result = scsi_add_host(shost, &intf->dev);
 	if (result)
 		goto free_streams;
 
 	scsi_scan_host(shost);
-	usb_set_intfdata(intf, shost);
 	return result;
 
 free_streams:
 	uas_free_streams(devinfo);
+	usb_set_intfdata(intf, NULL);
 set_alt0:
 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
 	if (shost)