message: Remove debug code from `multi.c`
diff: #define own
  -int wasmer_last_error_length(void);
  -void wasmer_last_error_message(char*, int);
  -
  -// Use the last_error API to retrieve error messages
  -void print_wasmer_error()
  -{
  - int error_len = wasmer_last_error_length();
  - printf("Error len: `%d`\n", error_len);
  - char *error_str = malloc(error_len);
  - wasmer_last_error_message(error_str, error_len);
  - printf("Error str: `%s`\n", error_str);
  -}
  -
  // A function to be called from Wasm code.
  own wasm_trap_t* callback(
  const wasm_val_vec_t* args, wasm_val_vec_t* results
  @@ -143,7 +130,6 @@ int main(int argc, const char* argv[]) {
  wasm_val_vec_t results = WASM_ARRAY_VEC(res);
  if (wasm_func_call(run_func, &args, &results)) {
  printf("> Error calling function!\n");
  - print_wasmer_error();
  return 1;
  }
  