hurd: Use the RETURN_ADDRESS macro

This gives us PAC stripping on AArch64.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240323173301.151066-6-bugaevc@gmail.com>

sysdeps/mach/hurd/init-first.c

@@ -222,7 +222,7 @@ _hurd_stack_setup (void **argptr)
      this may not be a valid pointer in case we're supposed to receive the
      arguments from the exec server, so we can not dereference it yet.  */
 
-  void *caller = __builtin_extract_return_addr (__builtin_return_address (0));
+  void *caller = RETURN_ADDRESS (0);
   /* Init the essential things.  */
   first_init ();