modesetting: fix memory leak caused by TearFree
When compositing in Xorg, dirty->data is marked, RegionIntersect() wil1allocate space for the region to save dirty->data, afterwards the regionneeds to be released.
When compositing in Xorg, dirty->data is marked, RegionIntersect() wil1allocate space for the region to save dirty->data, afterwards the regionneeds to be released.