basics: fixup case fallthrough

[zougloub]

Thank you @lorf for the library.
Here's a minor fix that allows to take more options.

For reference, with an FT2232HL (hooked as per http://www.ftdichip.com/Support/Documents/AppNotes/AN_114_FTDI_Hi_Speed_USB_To_SPI_Example.pdf or also on my dear Bus Blaster v2):

export FTDI_INTERFACE=A FTDI_PINOUT=hwspi
BlueFlash.exe
BlueFlashCmd.exe -usb 1 identify

[lorf]

Great, thanks!

[GamedecH]

Hi, How can I compilate this realise (0.5.2) ? Whan I try to use make ( MinGW ) it ends with error.