Blender Git Loki

Cleanup: Correct order of guard and lock in moviecache_valfree

Fix own mistake in rB7061d1e39fe

In my attempt to quickly address T92838, along with the original bug, I
made a nonsensical choice to use the limiter lock to guard the check
against the cache item itself. While harmless, it is not necessary and
semantically wrong / potentially confusing to future readers of the code.

Differential Revision: https://developer.blender.org/D13122