minor #16029 [Validator] [Validation] improve code for counting errors (nicolas-grekas)

This PR was merged into the 4.4 branch.

Discussion
----------

[Validator] [Validation] improve code for counting errors

Replaces #15983
Follows the discussion at symfony/symfony#43643

Commits
-------

3cae3a1 [Validation] improve code for counting errors

Author: javiereguiluz

validation/raw_values.rst

@@ -25,7 +25,7 @@ address. From inside a controller, it looks like this::
             $emailConstraint
         );
 
-        if (0 === count($errors)) {
+        if (!$errors->count()) {
             // ... this IS a valid email address, do something
         } else {
             // this is *not* a valid email address