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.
output: normalizeIndent`
                function MyComponent(props) {
                  function handleNext1() {
                    console.log('hello');
                  }
                  const handleNext2 = useCallback(() => {
                    console.log('hello');
                  });
                  let handleNext3 = function() {
                    console.log('hello');
                  };
                  useEffect(() => {
                    handleNext1();
                    return Store.subscribe(() => handleNext1());
                  }, [handleNext1]);
                  useLayoutEffect(() => {
                    handleNext2();
                    return Store.subscribe(() => handleNext2());
                  }, [handleNext2]);
                  useMemo(() => {
                    handleNext3();
                    return Store.subscribe(() => handleNext3());
                  }, [handleNext3]);
                  return (
                    <div
                      onClick={() => {
                        handleNext1();
                        setTimeout(handleNext2);
                        setTimeout(() => {
                          handleNext3();