removed extra parenthesis around argument for set state arrow function

Author: imsolost

javascript/ql/src/React/InconsistentStateUpdate.qhelp

@@ -36,7 +36,7 @@ Instead, the callback form of <code>setState</code> should be used:
 </p>
 
 <sample language="javascript">
-this.setState((prevState) => ({
+this.setState(prevState => ({
   counter: prevState.counter + 1
 }));
 </sample>