Update ProductPriceTest.php for Unit test

Author: aasim110

dev/tests/api-functional/testsuite/Magento/GraphQl/Catalog/ProductPriceTest.php

@@ -1225,7 +1225,7 @@ private function assertPrices($expectedPrices, $actualPrices, $currency = 'USD')
             );
             $this->assertEqualsWithDelta(
                 $expected['discount']['amount_off'],
-                ($actual['regular_price']['value'] - round($actual['final_price']['value'],2)),
+                ($actual['regular_price']['value'] - round($actual['final_price']['value'], 2)),
                 self::EPSILON
             );
             $this->assertEqualsWithDelta(