[BUGFIX] Correctly render information boxes if image rendering tests fail

Due to a naming mismatch in the refactoring during #87724 it was tried to
render information boxes based on the parent container element.

The code is adjusted now to reference the correct object in the
rendering loop.

Resolves: #91831
Related: #87724
Releases: master, 10.4
Change-Id: Ib80f0f04a9e7ce164be1cd6717fd105d3339b269
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/65060


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>