io.defs comment fix

[Alfred M. Szmidt]

Fixes a outdated comment, the id_tag argument hasn't existed since
about 1996.

hurd/ChangeLog
2004-10-31  Alfred M. Szmidt  <ams@gnu.org>

        * io.defs (io_select): Comment fix.

--- hurd/io.defs        11 Jun 2002 23:37:16 +0200      1.36
+++ hurd/io.defs        31 Oct 2004 10:21:13 +0100      
@@ -1,5 +1,5 @@
 /* Definitions for generic IO interface
-   Copyright (C) 1991,93,94,95,96,99,2001,02 Free Software Foundation, Inc.
+   Copyright (C) 1991,93,94,95,96,99,2001,02,04 Free Software Foundation, Inc.
 
 This file is part of the GNU Hurd.
 
@@ -146,9 +146,7 @@ routine io_get_icky_async_id (
 
 /* SELECT_TYPE is the bitwise OR of SELECT_READ, SELECT_WRITE, and SELECT_URG.
    Block until one of the indicated types of i/o can be done "quickly", and
-   return the types that are then available.  ID_TAG is returned as passed; it
-   is just for the convenience of the user in matching up reply messages with
-   specific requests sent.  */
+   return the types that are then available.  */
 /* INTR */
 routine io_select (
        io_object: io_t;