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.
}
            const isDirectlyInsideEffect = fnScope.block === node;
            if (isDirectlyInsideEffect) {
              
              setStateInsideEffectWithoutDeps = key;
            }
          });
        });
        if (setStateInsideEffectWithoutDeps) {
          const {suggestedDependencies} = collectRecommendations({
            dependencies,
            declaredDependencies: [],
            stableDependencies,
            externalDependencies: new Set(),
            isEffect: true,
          });
          reportProblem({
            node: reactiveHook,
            message:
              `React Hook ${reactiveHookName} contains a call to '${setStateInsideEffectWithoutDeps}'. ` +
              `Without a list of dependencies, this can lead to an infinite chain of updates. ` +
              `To fix this, pass [` +
              suggestedDependencies.join(', ') +
              `] as a second argument to the ${reactiveHookName} Hook.`,
            suggest: [
              {
                desc: `Add dependencies array: [${suggestedDependencies.join(
                  ', ',
                )}]`,
                fix(fixer) {