Comment 14 for bug 613273

There was a concern that udev is still running at this point, so I added a `ps` right after `udevadm control --timeout=61 --exit` and the result is this:
    Begin: Running /scripts/local-bottom ... done.
    done.
    Begin: Running /scripts/init-bottom ... PID USER VSZ STAT COMMAND
        1 0 4460 S /bin/sh /init ro
        2 0 0 SW [kthreadd]
        3 0 0 SW [ksoftirqd/0]
        4 0 0 SW [kworker/0:0]
        5 0 0 SW [kworker/u:0]
        6 0 0 SW [migration/0]
        7 0 0 SW [migration/1]
        8 0 0 SW [kworker/1:0]
        9 0 0 SW [ksoftirqd/1]
       10 0 0 SW [kworker/0:1]
       11 0 0 SW< [cpuset]
       12 0 0 SW< [khelper]
       13 0 0 SW< [netns]
       14 0 0 SW [sync_supers]
       15 0 0 SW [kworker/u:1]
       16 0 0 SW [bdi-default]
       17 0 0 SW< [kintegrityd]
       18 0 0 SW< [kblockd]
       19 0 0 SW< [ata_sff]
       20 0 0 SW [khubd]
       21 0 0 SW< [md]
       22 0 0 SW [kworker/1:1]
       24 0 0 SW [khungtaskd]
       25 0 0 SW [kswapd0]
       26 0 0 SWN [ksmd]
       27 0 0 SWN [khugepaged]
       28 0 0 DW [fsnotify_mark]
       29 0 0 SW [ecryptfs-kthrea]
       30 0 0 SW< [crypto]
       38 0 0 SW< [kthrotld]
       39 0 0 SW [scsi_eh_0]
       40 0 0 SW [scsi_eh_1]
       41 0 0 SW [kworker/u:2]
       42 0 0 SW [kworker/u:3]
      298 0 0 SW [jbd2/vda-8]
      299 0 0 SW< [ext4-dio-unwrit]
      303 0 4456 S /bin/sh -e /scripts/init-bottom/udev
      305 0 4460 R ps
    done.
    run-init: nuking initramfs contents: Directory not empty
    [ 6.397128] Kernel panic - not syncing: Attempted to kill init!
    [ 6.397849] Pid: 1, comm: run-init Not tainted 3.0.0-12-server #20-Ubuntu
    [ 6.398715] Call Trace:
    [ 6.399018] [<ffffffff815e8184>] panic+0x91/0x194
    [ 6.399609] [<ffffffff810626c5>] forget_original_parent+0x245/0x250
    [ 6.400424] [<ffffffff810626e7>] exit_notify+0x17/0x150
    [ 6.401102] [<ffffffff81062feb>] do_exit+0x1fb/0x440
    [ 6.401660] [<ffffffff81063387>] sys_exit+0x17/0x20
    [ 6.402255] [<ffffffff81606c02>] system_call_fastpath+0x16/0x1b