Error handling

[recmo]

On 2020-04-07 @recmo wrote in 6ddf787 “Fix lints”:

Error handling

        if length == 0 {
            return;
        }
        // TODO: Address must be page aligned
        let address = self.as_mut_ptr() as *mut ();
        // TODO: Error handling
        advise(address, length, advice).unwrap_or_else(|_| panic!("MADVISE failed"));
    }
}

// Blanket implementation for slices

From algebra/primefield/src/fft/prefetch.rs:80