Generally, you don't need to file an amended partnership return if the corrections have no effect on the income reported to the partners. You can fix Schedule M-2 next year, usually with a Prior Period Adjustment. Or simply revise the prior year Schedule M-2 to match the prior year balance sheet. Be prepared to answer questions from the partners should they ask.
Also, you might consider filing an extension next year in case you need to fix something after you first file the partnership return. The rules allow you to file a "superseding" return within the filing deadline (including extensions) rather than the formal process of an amended return.