[$] Problems emerge for a unified /dev/*random

In mid-February, we reported on the plan tounite the two kernel devices that provide random numbers;/dev/urandom was to effectively just be another way to access therandom numbers provided by /dev/random. That change made it asfar as the mainline during the Linux 5.18 merge window, but it wasquickly reverted when problems were found. It may be possible todo that unification someday, but, for now, there are environments that needtheir random numbers early on-without entropy or the "Linus jitter dance"being available on the platform.