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.
(id.parent.type === 'CallExpression' ||
                id.parent.type === 'OptionalCallExpression') &&
              id.parent.callee === id
            ) {
              isFunctionCall = true;
              break;
            }
          }
          if (!isFunctionCall) {
            return;
          }
          
          
          
          missingCallbackDep = missingDep;
        });
        if (missingCallbackDep !== null) {
          extraWarning =
            ` If '${missingCallbackDep}' changes too often, ` +
            `find the parent component that defines it ` +
            `and wrap that definition in useCallback.`;
        }
      }
      if (!extraWarning && missingDependencies.size > 0) {
        let setStateRecommendation = null;
        missingDependencies.forEach(missingDep => {
          if (setStateRecommendation !== null) {
            return;
          }
          const usedDep = dependencies.get(missingDep);