MC-23193: Tier Prices error on product update

Author: yelahin-serhiy

app/code/Magento/Catalog/Model/Product/Attribute/Backend/TierPrice/UpdateHandler.php

@@ -96,12 +96,7 @@ public function execute($entity, $arguments = [])
             $productId = (int)$entity->getData($identifierField);
 
             // prepare original data to compare
-            $origPrices = [];
-            $originalId = $entity->getOrigData($identifierField);
-            if (empty($originalId) || $entity->getData($identifierField) == $originalId) {
-                $origPrices = $entity->getOrigData($attribute->getName());
-            }
-
+            $origPrices = $entity->getOrigData($attribute->getName());
             $old = $this->prepareOldTierPriceToCompare($origPrices);
             // prepare data for save
             $new = $this->prepareNewDataForSave($priceRows, $isGlobal);