Eliminate proto_tree_add_text from some dissectors.

Change-Id: Ib6024307e85d6c23decf40e9759f549c19ffe136
Reviewed-on: https://code.wireshark.org/review/3318
Petri-Dish: Michael Mann <mmann78@netscape.net>
Petri-Dish: Evan Huus <eapache@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>