Well the biggest initial change is that Crispi (a Duce ante-litteram) will remain in power sometime more...not that much he is old, health is not really good and there is a lot of skeleton in the closet that wait only to be discovered as the man was not very like by many politicians or even by the King.
Relations with France while the man is in charge will remain awful, and Italy will remain a solid member of the Triple Alliance.
Internally a succesfull ethiopian campaign mean that a presidente del consiglio, will have more leeway to pursuit a personal foreign policy (the Adowa precedent greatly weakened this notion creating problem during the intervention in Crete and CHina).
Said that the war was both costly and the general population was not really in favor of it so things will be closed quickly with some enlargement of Eritrea and Abyssinia being a somewhat protectorate of Italy.
Here start the little problem, at the moment italian troops are stationed at Cassala in Sudan, having conquered the city from the Mahdist, after Adwua in OTL the italian goverment decided to retreat from there to secure Eritrea.
In case of victory instead we will see the italian garrison growing, the problem is that the city it's out of the zone assigned to Italy but the British will return in Sudan only in 97, so an italian goverment can decide to not vacate the place.
No humiliation in Ethiopia also mean that Giolitti will feel less pressured to obtain a great military victory in Libya and accepting a deal that keep the formal possession of the place in the hand of the Ottoman but let the Italian de facto rule it, will be palatable.