Eliminate proto_tree_add_text from several dissectors.

Change-Id: I6d3125f15d268edd47ef74dd655eb86cb25ee52d
Reviewed-on: https://code.wireshark.org/review/5047
Reviewed-by: Michael Mann <mmann78@netscape.net>
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>