wineusb.sys: Mark child PDOs as removed as soon as they are hot-unplugged.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/wineusb.sys/wineusb.c

@@ -144,6 +144,7 @@ static void remove_usb_device(libusb_device *libusb_device)
     {
         if (device->libusb_device == libusb_device)
         {
+            device->removed = TRUE;
             list_remove(&device->entry);
             break;
         }