**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
`,
    `
      // Valid because functions can call functions.
      function normalFunctionWithConditionalFunction() {
        if (cond) {
          doSomething();
        }
      }
    `,
    `
      // Valid because functions can call functions.
      function functionThatStartsWithUseButIsntAHook() {
        if (cond) {
          userFetch();
        }
      }
    `,
    `
      // Valid although unconditional return doesn't make sense and would fail other rules.
      // We could make it invalid but it doesn't matter.
      function useUnreachable() {
        return;
        useHook();
      }
    `,
    `
      // Valid because hooks can call hooks.
      function useHook() { useState(); }
      const whatever = function useHook() { useState(); };
      const useHook1 = () => { useState(); };