[ARM] Cast string pointers to int to avoid compiler warnings.

[Christophe Lyon]

ping?

This is similar to what is done in other places in the same source file.
On Mon, 1 Oct 2018 at 23:30, Christophe Lyon <christophe.lyon@linaro.org> wrote:
>
> Hi,
>
> While building newlib for ARM, I noticed that GCC complains about
> implicit casts. This small patch makes them explicit, just like in
> other parts of the same source file.
>
> OK?
>
> Christophe