doc: Fixed copy/paste errors in DSM snippets

The comments make sense only for the first button, the one that changes
the text label.

Change-Id: I984f3eff7c797cbccafcba2a0eeaaff9001094e6
Reviewed-by: Brett Stottlemyer <bstottle@ford.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>