Fix skipif condition

Author: nikic

ext/standard/tests/serialize/splobjectstorage_negative_count.phpt

@@ -1,7 +1,7 @@
 --TEST--
 OSS-Fuzz: Unserializing SplObjectStorage with negative number of elements
 --SKIPIF--
-<?php if (PHP_INT_SIZE != 4) die("skip requires 64-bit"); ?>
+<?php if (PHP_INT_SIZE != 8) die("skip requires 64-bit"); ?>
 --FILE--
 <?php