The tax basis ytour corporation has in the investment is your burden to maintain, not the partnership's. Once they are notified of your allocation of the 754 purchase price adjustment, they report them as you see on your K-1. They do NOT typically maintain your tax basis information, although some do.
It is an expense, and one you should claim that way.
The corporate investment in the partnership interest, let's say for $10,000, is reported as an asset, likely under investments, for $10,000. Income you report adds to basis, losses and 754 expenses would decrease basis. Payments from the partnership reduce basis, additional investments needed in the partnership would increase basis.
Let's say this is the first year, you paid $10,000, and reported income of $1,100 and a 754 expense of $80. Your basis at year-end would be $10.920. If you never received any cash, and sold the interest january 1, 2016, your basis for gain or loss would be $10,920.
You report both the $1,000 income and $80 expense on 1120. The basis question is addressed most often upon sale.