fix: rules-of-hooks not detecting hooks in hooks

[marvinhagemeister]

This fixes an error in the rules-of-hooks linting rule that didn't detect when a hook is inside another hook as part of a variable declaration.

// Valid, but would print a lint error
function useFoo() {
  const foo = useState(0);
}

Upon looking at the code further it turns out that the variable declaration handling is less involved.