radv/winsys: Fix memory leak.

Fix warning reported by Coverity Scan.

Resource leak (RESOURCE_LEAK) leaked_storage: Variable handles going out of scope leaks the storage it points to.

Fixes 485ea7d7 ("radv/winsys: pass the buffer list via the CS ioctl for less CPU overhead") Signed-off-by: Vinson Lee vlee@freedesktop.org

cc: @hakzsam