cmake HAS_READCHUNKS examples

Unidata/netcdf-c cmake/dependencies.cmake :203 

check_symbol_exists(H5Dread_chunk "hdf5.h" HAS_READCHUNKS)

Unidata/netcdf-c cmake/dependencies.cmake :205 

check_symbol_exists(H5Dread_chunk2 "hdf5.h" HAS_READCHUNKS)