Is it worth adding 115 calories over my deficit to hit my protein goal?

Fat loss is a journey. Getting tied up with trying to hit your macros exactly just makes that journey harder to traverse. Don't get me wrong, macros are an important and helpful guide. Straying a little off the numbers won't matter much in the long run. Exceed the calories a bit, or come up a little short on protein for the day - which ever way you go is the right answer as long as your weekly and monthly averages fit into your forever-way-of-eating plan.

And alternative option: consider whether you really need 120gr of protein. You've not provided any further information about yourself and your diet goals, thus it's difficult to give more detailed answers.

You really haven't given us enough relevant information.

Mostly, I agree with ninerbuff: Reduce carbs or fat a bit, carbs being the most flexible, to make more calorie room. Changing eating patterns in that way as a general habit would be a good strategy.

Note: If this is a "just this one day" thing, it honestly doesn't matter much. Eat a bit less protein just one day here and there occasionally, or a few more calories just occasionally . . . really not a big deal. Macronutrients aren't a magic spell where we need to get every syllable precisely accurate, or demons get released. Pretty close to macronutrient goals, on average over a small number of days: That's just fine. Ditto for calories: Averages matter, not daily exactitude, because our bodies don't reset at midnight even though MFP does.

From a weight loss perspective, if you ate 115 calories more every single day, you'd lose weight approximately 0.23 pounds (3.68 ounces) per week slower than if you didn't eat those 115 extra calories every day. Depending on your current weight loss rate, that may not be a big deal. Your call.

I'd also question the 120g protein goal. It may be fine. Generally, for most people, something in the range of 0.6-0.8g protein per pound of healthy goal weight, as a daily minimum, is adequate. Someone with an intense exercise schedule or other special conditions may benefit from more, maybe 1g per pound of goal weight. Something around 1.2g/pound is about the max I've seen with what I considered rational justification. Protein goals can be based on healthy goal weight. We don't need lots of extra protein to maintain our fat mass, it's primarily to maintain our lean mass. A grams-based estimate can be more useful than a percent of calories estimate.

If you'd like an evidence based protein needs estimate, there's a calculator and guide (from an outfit generally regarded as neutral, i.e., not trying to sell you supplements) here:

https://examine.com/protein-intake-calculator/
https://examine.com/guides/protein-intake/

Somewhere in the guide, it mentions that it can be OK to use a goal weight in the calculator rather than current weight, if currently seriously overweight.

FWIW, for myself, at 5'5", female, athletically active, I target a minimum of 100g protein daily, figuring that that's around 0.8g per pound of a sensible weight for me personally, or a bit over 1g per pound of estimated lean mass for me. I don't seem to have any negative consequences at that level.

Best wishes!