Cleanup format in debug message in task_cgroup_init.

- %lu and casting to unsigned long will truncate values > 2TB
- Format of %.4g for (unsigned long) totalram is incorrect. And casting to
  (unsigned long) is incorrect anyways.
- %lu for memory_swappiness was incorrect, this is (uint64_t)
  not (unsigned long)
- don't print memory_swappiness as hex, instead indicate if set or not, and
  avoid printing NO_VAL64 if not set
- fix spacing and spread out the ternary operators