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.
`React Hook ${reactiveHookName} received a function whose dependencies ` +
              `are unknown. Pass an inline function instead.`,
          });
          return; 
      }
      
      reportProblem({
        node: reactiveHook,
        message:
          `React Hook ${reactiveHookName} has a missing dependency: '${callback.name}'. ` +
          `Either include it or remove the dependency array.`,
        suggest: [
          {
            desc: `Update the dependencies array to be: [${callback.name}]`,
            fix(fixer) {
              return fixer.replaceText(
                declaredDependenciesNode,
                `[${callback.name}]`,
              );
            },
          },
        ],
      });
    }
    return {
      CallExpression: visitCallExpression,
    };
  },
};
function collectRecommendations({