[BUGFIX] Edit/Delete postings not possible because of missing token

When viewing a posting as board admin the edit/delete links are
missing the value of the "&token" param.

This patch generates the tokens before calling the "list_post"
method.

Change-Id: Ic48cc33a0fcac24b9d57b6fb5244fbf874801525
Releases: 1.9.x, master
Resolves: #56064
Reviewed-on: http://review.typo3.org/29067
Reviewed-by: Gernot Ploiner <gp@webprofil.at>
Tested-by: Gernot Ploiner <gp@webprofil.at>
Reviewed-by: Simon Schaufelberger <simonschaufi@googlemail.com>
Tested-by: Simon Schaufelberger <simonschaufi@googlemail.com>