Fixed db->close() and db->free_result() functions
diff --git a/system/database/drivers/pdo/pdo_result.php b/system/database/drivers/pdo/pdo_result.php
index c386586..5e136f5 100644
--- a/system/database/drivers/pdo/pdo_result.php
+++ b/system/database/drivers/pdo/pdo_result.php
@@ -111,9 +111,8 @@
 	 */
 	function free_result()
 	{
-		if (is_resource($this->result_id))
+		if (is_object($this->result_id))
 		{
-			pdo_free_result($this->result_id);
 			$this->result_id = FALSE;
 		}
 	}