eslint-plugin-react-hooks version: 4.2.0

## Steps To Reproduce

I know it shouldn't exist in production code, but it's annoying while editing some files.

```js
import React, { useEffect } from "react";

const App = () => {
  useEffect(); // <-
  return null;
};

export default App;
```

Link to code example: https://codesandbox.io/s/polished-sun-3wr27?file=/src/App.js

## The current behavior

ESLint crashed.

```
TypeError: Cannot read property 'type' of undefined
```

## The expected behavior

ESLint doesn't crash but reports an error instead.
const queue = [start];
  let item = null;
  while (queue.length) {
    item = queue.shift();
    if (isSameIdentifier(item, target)) {
      return item;
    }
    if (!isAncestorNodeOf(item, target)) {
      continue;
    }
    for (const [key, value] of Object.entries(item)) {
      if (key === 'parent') {
        continue;
      }
      if (isNodeLike(value)) {
        value.parent = item;
        queue.push(value);
      } else if (Array.isArray(value)) {
        value.forEach(val => {
          if (isNodeLike(val)) {
            val.parent = item;
            queue.push(val);
          }
        });
      }
    }
  }
  return null;
}
function joinEnglish(arr) {