Incorrect warning message on scalar finalizer

[Bug 58175 ](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58175) persists in GCC 6.1.1., more specifically, our use of finalizors results in the following erroneous warning message during compilation.

```

     use cpu_timer_library, only: &
        1
Warning: Only array FINAL procedures declared for derived type ‘cputimer’ defined at (1), suggest also scalar one [-Wsurprising]
```
