[Validator] ConstraintValidatorTestCase: add missing return value to mocked validate method calls

Author: ogizanagi

Test/ConstraintValidatorTestCase.php

@@ -177,7 +177,8 @@ protected function expectValidateAt($i, $propertyPath, $value, $group)
             ->willReturn($validator);
         $validator->expects($this->at(2 * $i + 1))
             ->method('validate')
-            ->with($value, $this->logicalOr(null, [], $this->isInstanceOf('\Symfony\Component\Validator\Constraints\Valid')), $group);
+            ->with($value, $this->logicalOr(null, [], $this->isInstanceOf('\Symfony\Component\Validator\Constraints\Valid')), $group)
+            ->willReturn($validator);
     }
 
     protected function expectValidateValueAt($i, $propertyPath, $value, $constraints, $group = null)
@@ -189,7 +190,8 @@ protected function expectValidateValueAt($i, $propertyPath, $value, $constraints
             ->willReturn($contextualValidator);
         $contextualValidator->expects($this->at(2 * $i + 1))
             ->method('validate')
-            ->with($value, $constraints, $group);
+            ->with($value, $constraints, $group)
+            ->willReturn($contextualValidator);
     }
 
     protected function assertNoViolation()