[TASK] Change docComment of FlashMessageViewHelper

Change the docComment of FlashMessageViewHelper to match the new output

Resolves: #62603
Releases: master
Change-Id: Ie32a8e2f4eac3d18bccc059c85370d063eaa65c2
Reviewed-on: http://review.typo3.org/33693
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <andreas.fernandez@aspedia.de>
Tested-by: Andreas Fernandez <andreas.fernandez@aspedia.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>