Function potrf 

pub fn potrf<T: SolverScalar>(
    handle: &DnHandle,
    uplo: Fill,
    n: i32,
    a: &mut DeviceBuffer<T>,
    lda: i32,
    info: &mut DeviceBuffer<i32>,
) -> Result<()>

Cholesky factorization: A = L * Lᵀ (or Uᵀ * U). Overwrites a.