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.
}
      }
      let currentScope = reference.from;
      while (currentScope !== scope && currentScope != null) {
        currentScope = currentScope.upper;
      }
      if (currentScope !== scope) {
        
        
        if (!isAncestorNodeOf(declaredDependenciesNode, reference.identifier)) {
          return true;
        }
      }
    }
    return false;
  }
  return constructions.map(([ref, depType]) => ({
    construction: ref.defs[0],
    depType,
    isUsedOutsideOfHook: isUsedOutsideOfHook(ref),
  }));
}
/**
 * Assuming () means the passed/returned node:
 * (props) => (props)
 * props.(foo) => (props.foo)
 * props.foo.(bar) => (props).foo.bar
 * props.foo.bar.(baz) => (props).foo.bar.baz
 */
function getDependency(node) {