Restrict-qualify iolog_path_escapes like we do with check_iolog_path

[AZero13]

This matches the same functions in check_iolog_path.

[millert]

Do you think it is worth adding restrict to copy_fn here?

struct iolog_path_escape {
    const char *name;
    size_t (*copy_fn)(char * restrict, size_t, void * restrict);
};

I don't believe it has any real effect but would act as a hint to use restrict in the various copy functions.

[AZero13]

Do you think it is worth adding restrict to copy_fn here?

struct iolog_path_escape {
    const char *name;
    size_t (*copy_fn)(char * restrict, size_t, void * restrict);
};

I don't believe it has any real effect but would act as a hint to use restrict in the various copy functions.

I do actually!