usb/77184: [umass] [panic] kernel panic on USB device disconnect, even if not detected

[Yuri]

Crash is gone.

But there is something wrong. I did the following steps:
1. plug the camera into USB and mount it
2. unplug the camera without unmounting it -- no crash, looks good.
3. mount still exists. that's ok.
4. umount /mnt/camera
     -- command says: "Device Busy", this looks reasonable.
5. umount -f /mnt/camera
     -- mount is gone.
6. repeated steps 1...4
     on step 4 umount command without -f flag doesn't complain
     about device busy any more. This is really strange and this
     means that device disconnect or unmount hasn't been done
     cleanly and something is different now.


So this issue has to be cleared -- outcome of steps 1..5 should always 
be the same.

Yuri