This is a pretty stupid question dude... And the saltwater crocodile would win because it's good in land and water and it's biting force is stronger. The great whites teeth are meant for eating seals and fish.
If the two ever fought, the great white would probably win. They can move faster for a longer time. My question would ask why the two would ever fight in the first place. They don't see much of one another.
There is a book called The Barefoot Mailman. Written in Florida, maybe 100 years ago that tells the story of among other things a fight between crocodiles and sharks, I don't remember which were said to have won.
The Great White would win. It is a stronger swimmer and more maneuverable. The crocodile's hunting strategy depends on lying in wait and catching its victim by surprise. After it's first initial lunge the crocodile does not pursue its prey.