Apply suggestions from code review

Author: paulbalandan

system/Database/BaseBuilder.php

@@ -659,7 +659,7 @@ protected function whereHaving(string $qbKey, $key, $value = null, string $type
                     $op = trim(current($op));
 
                     if (substr($k, -1 * strlen($op)) === $op) {
-                        $k  = rtrim(substr($k, 0, -1 * strlen($op)));
+                        $k  = rtrim(substr($k, 0, -strlen($op)));
                         $op = " {$op}";
                     } else {
                         $op = '';
@@ -680,7 +680,7 @@ protected function whereHaving(string $qbKey, $key, $value = null, string $type
                 $op = ' IS NULL';
             } elseif (preg_match('/\s*(!?=|<>|IS(?:\s+NOT)?)\s*$/i', $k, $match, PREG_OFFSET_CAPTURE)) {
                 $k  = substr($k, 0, $match[0][1]);
-                $op = ($match[1][0] === '=' ? ' IS NULL' : ' IS NOT NULL');
+                $op = $match[1][0] === '=' ? ' IS NULL' : ' IS NOT NULL';
             } else {
                 $op = '';
             }