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.
],
    },
    {
      code: normalizeIndent`
        function Counter() {
          let [count, setCount] = useState(0);
          let increment = useCustomHook();
          useEffect(() => {
            let id = setInterval(() => {
              setCount(count => count + increment);
            }, 1000);
            return () => clearInterval(id);
          }, []);
          return <h1>{count}</h1>;
        }
      `,
      
      
      
      errors: [
        {
          message:
            "React Hook useEffect has a missing dependency: 'increment'. " +
            'Either include it or remove the dependency array.',
          suggestions: [
            {
              desc: 'Update the dependencies array to be: [increment]',
              output: normalizeIndent`
                function Counter() {
                  let [count, setCount] = useState(0);