Functions can be statically inlined

[henkmuller]

lib_nn/lib_nn/src/cpp/Filter2D.cpp

Line 31 in b2e8858

void conv_calc_output_pixel_slice(int8_t *Y, int8_t *X, int32_t h,

This function (and its depth wise counterpart earlier on in the file), can very likely be made 'static inline void' without costing any extra memory, but improving execution speed.