Null check rootNode before calling getScope

Author: crnhrv

lib/util/propTypes.js

@@ -372,7 +372,8 @@ module.exports = function propTypesInstructions(context, components, utils) {
    */
   function resolveValueForIdentifierNode(node, rootNode, callback) {
     if (
-      node
+      rootNode
+      && node
       && node.type === 'Identifier'
     ) {
       const scope = getScope(context, rootNode);