Fix issue with Kraken 2

Bug Fix

What does this MR do?

This MR properly handles devices that do not have a serial number present within in the hid_info. (liquidctl)

Related issues

Fixes #94 (closed)

Checklist

• Application works as expected when running from source
• There are dependency changes
• Liquidctl device mock tests are successful (if applicable)
• Any needed documentation changes have been made
• This MR is ready to be merged