Fix c_recv_buffer using c_byte

[kennyhml]

In the device class, you initialize the receive buffer as 12 or 24 signed bytes c_byte depending on the device type.

Later in the device_io_result class, that data is passed and converted to bytes, which causes an error

bytes must be in range(0, 256).

This happened because signed bytes are used for the recv buffer, please consider to use c_ubyte to fix this issue.

When capturing strokes, if you are using a debugger for example, you will not be able to use your devices until you restart your computer.