Simplify some code with null coalesce operator

Author: javiereguiluz

Extension/Core/DataTransformer/IntegerToLocalizedStringTransformer.php

@@ -34,7 +34,7 @@ public function __construct($grouping = false, $roundingMode = self::ROUND_DOWN,
             @trigger_error(sprintf('Passing a precision as the first value to %s::__construct() is deprecated since Symfony 4.2 and support for it will be dropped in 5.0.', __CLASS__), \E_USER_DEPRECATED);
 
             $grouping = $roundingMode;
-            $roundingMode = null !== $locale ? $locale : self::ROUND_DOWN;
+            $roundingMode = $locale ?? self::ROUND_DOWN;
             $locale = null;
         }
 

Extension/Core/Type/TextType.php

@@ -62,6 +62,6 @@ public function transform($data)
      */
     public function reverseTransform($data)
     {
-        return null === $data ? '' : $data;
+        return $data ?? '';
     }
 }