I have memory leaks.

I have memory leaks... I don't know the cause of it, but I suspect it has something to do with the calloc prostitute I slept with. I'm going to the doctor later to have a my memory analyzed. Lets hope it's nothing terminal.

instead let the caller allocate it first and pass you the pointer to initialize it
So instead of having the allocation done in the function that creates the object, you now need an allocation call (of the proper size too) at each point the function is called? You just made the code more inefficient, duplicated, and even harder to maintain.