This finally allows running the test suite completely in a rootless container:
```
❯ podman run \
--user 0 \
-v /dev:/dev \
-v ./:/dracut \
-it \
quay.io/haraldh/dracut-fedora:33 \
bash -c 'cd /dracut; make DRACUT_NO_XATTR=1 check'
```
We no longer require any user intervention when testing dracut on
a local block device in qemu, assuming everything passes. If things fail,
we still might need to manually kill things.
First, add a check script to 99base to ensure that it will load its
prerequisites.
Second, disable the udev magic dracut normally uses when generating
test images -- it was causing random failures when creating the test
root filesystem, presumably due to race conditions between the
rootfs creation scripts and udev.
Third, consolidate the rootfs creation scripts into one script.
If we install copy-root as a mount hook, it will be run after the root fs
is mounted and it will make hte proc directory, allowing root filesystem
creation to finish without error.
Harald Hoyer