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.
function Foo({ activeTab }) {
          useEffect(() => {
            window.scrollTo(0, 0);
          }, [activeTab]);
        }
      `,
    },
    {
      
      
      code: normalizeIndent`
        function MyComponent(props) {
          useEffect(() => {
            console.log(props.foo.bar.baz);
          }, [props]);
          useEffect(() => {
            console.log(props.foo.bar.baz);
          }, [props.foo]);
          useEffect(() => {
            console.log(props.foo.bar.baz);
          }, [props.foo.bar]);
          useEffect(() => {
            console.log(props.foo.bar.baz);
          }, [props.foo.bar.baz]);
        }
      `,
    },
    {