./src/fwtool.c: In function 'add_data':
./src/fwtool.c:214:3: warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result [-Wunused-result]
   ftruncate(fileno(firmware_file), file_len);
   ^
./src/fwtool.c: In function 'extract_data':
./src/fwtool.c:367:3: warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result [-Wunused-result]
   ftruncate(fileno(firmware_file), dbuf.file_len);
   ^
