This seems to miss the exit code of the dracut process, which actualy
caused some issues in I8511669e188717494daf2bc1384a6dd346f942a4 where
it would have been much clearer to stop after the initramfs generation
failed.
Add some debug messages, and catch any errors from the final call.
Change-Id: I6f89441ec4709f5199535e15a7cc53a3a8af273d
When using combined with rhel7 image, the unregister of repos
has already happened, because it is executed under 60- ordering.
As dracut-regenerate may need to install extra packages for it,
it causes this step to fail, because it cannot find repos where
to pull the packages from.
Change-Id: I35e37df7990ad76a5004cb90fdd863ec743a5483
