[BUGFIX] Wrong use of FAL mediaElement properties

Change-Id: I7411dd9c2ab9623b76710d8eb9e748ae828f099d
Resolves: #61336
Reviewed-on: http://review.typo3.org/32655
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>