You need to split the income from the date you began operating as a partnership. I am assuming any 1099 you received (if you received any) were written to the proper entity or Employer Identification Number.
This is a new entity, correct with a different EIN. You do not record any loss for taking on a partner for free. You guys just became partners. The partnership just opened so you guys would deal with percentage splits. If you had been in business together and you bought out the other partner, that would be recordable.
Now If you are saying that the SMLLC was an asset of yours, you might be able to record the loss on your personal return, based on the valuation of the business. That would be a stretch to do so.
