change MAC address in USB device
This happens when you're using the generic Apple-supplied driver for the USB WiFi device, or if you're using a vendor-supplied driver that doesn't support changing the MAC address.

You'll need to install the vendor-supplied driver for your adapter, if you haven't already. If you cannot find a driver for your specific product, you might be able to find a driver for a different product using the same WiFi chipset - that might work.

When you have the vendor-supplied driver installed, the command you have supplied could then be able to change the MAC address.