va: allocator: Set the copied memory properly when poped from pool.
The current code does not set the copied memory correctly when it is popped from the surface cache pool.
- We forget to ref the allocator, which causes the allocator to be freed unexpectedi, and we get a crash later because of the memory violation.
- We forget to add ref_mems_count, which causes the surface leak because the surface can not be pushed back to the cache pool again.