Fix a typo in `cholesky_inverse` documentation (#110364)
Very small PR to fix a typo in [https://pytorch.org/docs/stable/generated/torch.cholesky_inverse.html](cholesky_inverse) doc.
According to the current doc, the function expects $A$, the symmetric positive-definite matrix, as input. But the examples given (and more important, the code) is using $u$ the cholesky decomposition of this matrix (like cholesky_solve).
Also, it provides a correct example of batch usage of this function.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110364
Approved by: https://github.com/lezcano
