main/busybox: Ensure all paths for busybox exists

When busybox --install is called (without parameters) the user is responsible to ensure all paths are created. While this is probably a bug in upstream busybox, it has been working this way since forever.

Until this is fixed upstream, lets ensure that if busybox is installed very early on, all paths needed do actually exist preventing 'no such file or directory' errors during install.

Signed-off-by: Olliver Schinagl oliver@schinagl.nl