MAGETWO-56065: [Flat] Filter Exception. review fixes

Author: valdislav

app/code/Magento/Catalog/Model/Indexer/Product/Flat/FlatTableBuilder.php

@@ -267,7 +267,7 @@ protected function _fillTemporaryFlatTable(array $tables, $storeId, $valueFieldS
 
             $select->joinLeft(
                 $temporaryTableName,
-                "e.${linkField} = ${temporaryTableName}.${linkField}",
+                sprintf('e.%1$s = %2$s.%1$s', $linkField, $temporaryTableName),
                 $columnsNames
             );
             $allColumns = array_merge($allColumns, $columnsNames);
@@ -281,7 +281,7 @@ protected function _fillTemporaryFlatTable(array $tables, $storeId, $valueFieldS
             if (!empty($columnValueNames)) {
                 $select->joinLeft(
                     $temporaryValueTableName,
-                    "e.${linkField} = " . $temporaryValueTableName . ".${linkField}",
+                    sprintf('e.%1$s = %2$s.%1$s', $linkField, $temporaryTableName),
                     $columnValueNames
                 );
                 $allColumns = array_merge($allColumns, $columnValueNames);