[TYPO3-core] FYI: Fixed bug #15394: Improve t3lib_SpriteManager code comments

[Christian Kuhn]

Steffen Ritter wrote:
> since you changed variable naming, too this one should not have been an 
> FYI commit...

Mmmh, I changed one local variable name, in a method without hooks and 
the class even doesn't have a xclass line -> complete nobrainer without 
possible sideeffects -> imho totally ok as FYI.

Regards
Christian