thread.c: fix obsoleted comment [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65818 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

thread.c

@@ -4439,7 +4439,7 @@ rb_thread_atfork(void)
     /* We don't want reproduce CVE-2003-0900. */
     rb_reset_random_seed();
 
-    /* For child, starting MJIT worker thread in this place which is safer than `after_fork_ruby`. */
+    /* For child, starting MJIT worker thread in this place which is safer than immediately after `after_fork_ruby`. */
     mjit_child_after_fork();
 }