Don't assign nullptr to custom_initial_data

[Alex-EEE]

Although most custom ops don't use this field, some now do, see https://github.com/tensorflow/tflite-micro/blob/main/tensorflow/lite/micro/kernels/ethos_u/ethosu.cc for example.

I think this is the correct way to fix this, do you see any issues with this patch? The pointer and size were already being saved off, just not used till this PR

[rafzi]

Thank you for your fix. This looks good to me.

However, you've sent the PR to the default branch r2.3, where you'd have to say ->init, see CI failure. Or maybe you meant to send this to another branch? The master is tracking the upstream tensorflow and has not been updated or pending some changes from here: https://github.com/cpetig/tflite_micro_compiler/pull/63