explicit_counter_loop false-positive when the counter is used after the loop

``` rust
                let mut character_count = 0;
                for (character_index, _) in text.char_indices() {
                    if character_index == insertion_point.index {
                        return Some(CharIndex(character_count))
                    }
                    character_count += 1
                }
                return Some(CharIndex(character_count))
```
