Fix compile warning on some gcc versions:
[libftdi] / ftdipp /
drwxr-xr-x   ..
-rw-r--r-- 1939 CMakeLists.txt
-rw-r--r-- 549 Makefile.am
-rw-r--r-- 11887 ftdi.cpp
-rw-r--r-- 5837 ftdi.hpp