null-dereference warning for the TFLM makefile build

[Advait Jain]

Hi everyone,

Just wanted to highlight that the way we patch flatbuffers as part of the Makefile build system has recently changed. And without the newly patched flatbuffers library, you will likely see a null-dereference warning described in this issue.

The fix is to remove the downloaded flatbuffers folder and re-make:
    rm -rf tensorflow/lite/micro/tools/make/downloads/flatbuffers
    make -f tensorflow/lite/micro/tools/make/Makefile test

Advait