Backport Apertis specific patch for uml
Backport Apertis specific patch:
- um: Add a generic "fd" vector transport
This patch is needed for the conversion to the libslirp helper in the uml image-building docker container.
The patch landed in kernel v5.8; as I am not sure when a kernel >5.8 will land in apertis, for now backport the patch to allow the work to continue.
After the kernel package has been built with this change included, the user-mode-linux
package will also need rebuilding.