pub fn parse_bus_device(text: &str) -> Option<(u8, u8)>Expand description
Parses bus:device as sscanf("%u:%u") would, into USB bus and address.
Whitespace around the bus number is ignored, and the device number ends
at its first non-digit, as %u stops there. None if there is no :,
either number is missing or not decimal, or either does not fit a u8.