Apply suggestion: replace concat([a]) with concat(a)

Co-Authored-By: Jordan Harband <ljharb@gmail.com>

Author: chiawendt

lib/util/usedPropTypes.js

@@ -364,7 +364,7 @@ module.exports = function usedPropTypesInstructions(context, components, utils)
           const propName = ast.getKeyValue(context, properties[k]);
 
           if (propName) {
-            propVariables.set(propName, parentNames.concat([propName]));
+            propVariables.set(propName, parentNames.concat(propName));
             usedPropTypes.push({
               allNames: parentNames.concat([propName]),
               name: propName,