Poll device in usbtest

commands/usbtest.c

@@ -194,6 +194,8 @@ grub_cmd_usbtest (grub_command_t cmd __attribute__ ((unused)),
 		  int argc __attribute__ ((unused)),
 		  char **args __attribute__ ((unused)))
 {
+  grub_usb_poll_devices ();
+
   grub_printf ("USB devices:\n\n");
   grub_usb_iterate (usb_iterate);