Set first parameter of memset * void* *

A simple test failed to match correctly if not changed to void*:
```cpp
#include <cstring>
#include <iostream>

int main()
{
// An array to zero
    int array[5] = {1, 3, 5, 7, 9};

// Index into the array
    int i;

// Zero the array
    std::memset(array, sizeof(array), '\0');

// Print the array
    for (i = 0; i < 5; ++i)
    {
        std::cout << "array[" << i << "]= " <<
                  array[i] << std::endl;
    }
    return (0);
}
```