Fixed some memory leak issues
In the previous commit ftdi_usb_find_all() was set to find all FTDI devices instead of specific IDs.
Currently I only know that 0x6001 and 0x6011 are supported so other devices are skipped if you know another ID that works please let us know.
libftdi checks for the following pids: 0x6001, 0x6010, 0x6011, 0x6014 (all vid 0x0403).
Fixed logic error in device selection.