**Do you want to request a *feature* or report a *bug*?**
bug
**What is the current behavior?**
React hooks linter fails with this piece of code

```js
function useHook() {
  const ref = React.useRef([1, 2, 3]);
  const res = []
  // valid because there are not unexpected returns
  if (ref.current) {
    for (let i = 0; i !== ref.current.length && !ref.current[i]; ++i ) {
      res.push(ref.current[i]);
    }
  }
  React.useLayoutEffect(() => {});
}
```

however a bit more usual for loop is handled as expected
```js
function useHook() {
  const ref = React.useRef([1, 2, 3]);
  const res = []
  if (ref.current) {
    for (let i = 0; i !== ref.current.length; ++i ) {
      res.push(ref.current[i]);
    }
  }
  React.useLayoutEffect(() => {});
}
```

**What is the expected behavior?**

Skip for looks without returns

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

eslint-plugin-react-hooks 0.0.0
let useHook2 = () => useState();
      useHook2 = () => { useState(); };
      ({useHook: () => { useState(); }});
      ({useHook() { useState(); }});
      const {useHook = () => { useState(); }} = {};
      ({useHook = () => { useState(); }} = {});
    `,
    `
      // Valid because hooks can call hooks.
      function useHook() {
        useHook1();
        useHook2();
      }
    `,
    `
      // Valid because hooks can call hooks.
      function createHook() {
        return function useHook() {
          useHook1();
          useHook2();
        };
      }
    `,
    `
      // Valid because hooks can call hooks.
      function useHook() {
        useState() && a;
      }
    `,
    `