Oops, missed a few places where EXIT_SUCCESS was being used.

Signed-off-by: Daniel Hunsaker <danhunsaker@gmail.com>
diff --git a/system/core/Output.php b/system/core/Output.php
index 1025703..25ecd49 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -696,7 +696,7 @@
 		if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && $last_modified <= strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']))
 		{
 			$this->set_status_header(304);
-			exit(EXIT_SUCCESS);
+			exit;
 		}
 		else
 		{