radv: add cache items to in memory cache when reading from disk

radv: add cache items to in memory cache when reading from disk

Otherwise we will leak them, load duplicates from disk rather
than memory and never write items loaded from disk to the apps
pipeline cache.

Fixes: fd24be134ffd 'radv: make use of on-disk cache'
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>