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.
`inside ${context.getSource(reactiveHook)}.`;
        }
      }
      if (!extraWarning && missingDependencies.size > 0) {
        
        
        let missingCallbackDep = null;
        missingDependencies.forEach(missingDep => {
          if (missingCallbackDep) {
            return;
          }
          
          const topScopeRef = componentScope.set.get(missingDep);
          const usedDep = dependencies.get(missingDep);
          if (usedDep.references[0].resolved !== topScopeRef) {
            return;
          }
          
          const def = topScopeRef.defs[0];
          if (def == null || def.name == null || def.type !== 'Parameter') {
            return;
          }
          
          let isFunctionCall = false;
          let id;
          for (let i = 0; i < usedDep.references.length; i++) {
            id = usedDep.references[i].identifier;
            if (
              id != null &&
              id.parent != null &&