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.
!callee.computed
        ) {
          callee = callee.property;
        }
        if (callee.type !== 'Identifier') {
          return false;
        }
        const id = def.node.id;
        const {name} = callee;
        if (name === 'useRef' && id.type === 'Identifier') {
          
          return true;
        } else if (name === 'useState' || name === 'useReducer') {
          
          if (
            id.type === 'ArrayPattern' &&
            id.elements.length === 2 &&
            Array.isArray(resolved.identifiers)
          ) {
            
            if (id.elements[1] === resolved.identifiers[0]) {
              if (name === 'useState') {
                const references = resolved.references;
                for (let i = 0; i < references.length; i++) {
                  setStateCallSites.set(
                    references[i].identifier,
                    id.elements[0],
                  );
                }
              }