wait_for_initramfs warning from kernel_init_freeable()

[Heiner Kallweit]

Since 97f8172f9a98 ("init/initramfs.c: do unpacking asynchronously") I get
the following warning early in the boot process from umh:
"wait_for_initramfs() called before rootfs_initcalls"
Some debugging lead me to the following call chain:

kernel_init_freeable()
-> do_basic_setup()
   -> driver_init()
      -> platform_bus_init()
         -> bus_register()
            -> kset_register()
               -> kobject_uvent()