MAGETWO-65099: [Performance] Optimize validation of swatches attributes

-- Backport

Author: Valeriy Nayda

app/code/Magento/Swatches/Test/Unit/Helper/DataTest.php

@@ -111,9 +111,11 @@ protected function setUp()
         );
 
         $this->attributeMock = $this->getMockBuilder(Attribute::class)
-            ->disableOriginalConstructor();
+            ->disableOriginalConstructor()
+            ->getMock();
         $this->metaDataPoolMock = $this->getMockBuilder(MetadataPool::class)
-            ->disableOriginalConstructor();
+            ->disableOriginalConstructor()
+            ->getMock();
 
         $serializer = $this->getMock(
             \Magento\Framework\Serialize\Serializer\Json::class,