update `trap` poisx link
diff --git a/shell/hush.c b/shell/hush.c
index 8f99b59..a7aa32a 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4529,7 +4529,7 @@
 /*
  * Built-ins
  */
-/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_28
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
  *
  * Traps are also evaluated immediately instead of being delayed properly:
  * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_11