TODO: cleanup and refactor iommu logic

[HikariKnight]

Based on feedback from Gnif the iommu probing logic might be able to be cleaned up a bit to avoid deep nesting
something like

func GetDevicesFromGroups(groups []int, related int, pArg *params.Params) []string {
  var output []string:
  if len(groups) == 0)
    return output

  alldevs := NewIOMMU()
  for _, group := range groups {
      if _, iommu_num := alldevs.Groups[group]; !iommu_num {
        errorcheck.ErrorCheck(fmt.Errorf("IOMMU Group %v does not exist", group))
        continue
      }

      .. do stuff ...
  }

  return output
}

and also cleanup with

for ... {
  if (a) {
    // do stuff
    continue;
  }

  if (b) {
    // do stuff
    continue;
  }
}

Writing this here as notes for myself incase i do not get to this before my vacation and the messages get drowned in discord.

The original code was written as it is now, it was easier to follow logic wise for my brain and was slated for a rewrite (which i forgot due to priorities elsewhere).