atusb/fw/usb/dfu.c (config_descriptor): correct alt settings off-by-one error
atusb/fw/usb/dfu.c (config_descriptor): correct alt settings off-by-one error

cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan