Some of the device memory objects had their host_pointer overwritten
with another CPU-side buffer after allocation. This leads to a leak of
host memory allocated by the device_memory.
There are few remaining places where the host_pointer is assigned and
those seems to be fine because the memory was not yet allocated with
a alloc() call.
While the approach in this change is not very ideal, it is small and
potentially could be ported to the LTS tracks. More ideal solution
would be to utilize device_vector::give_data().
Pull Request: https://projects.blender.org/blender/blender/pulls/126788