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 [data, setData] = useState(0);
          useEffect(() => {
            fetchData.then(setData);
          });
        }
      `,
      errors: [
        {
          message:
            `React Hook useEffect contains a call to 'setData'. ` +
            `Without a list of dependencies, this can lead to an infinite chain of updates. ` +
            `To fix this, pass [] as a second argument to the useEffect Hook.`,
          suggestions: [
            {
              desc: 'Add dependencies array: []',
              output: normalizeIndent`
                function Hello() {
                  const [data, setData] = useState(0);
                  useEffect(() => {
                    fetchData.then(setData);
                  }, []);
                }
              `,
            },
          ],
        },
      ],
    },
    {
      code: normalizeIndent`