Structure device not freed in error case

In case of an error in the call usb_device_get_fd()
the memory created by usb_open_device() is never
freed.

Added a call to usb_device_close in case of error to
release the allocated memory.

Change-Id: Iaa83674f000242d80604dd30c782236f7afd90c2
Fix, MountService now only sends one onShutDownComplete

The event onShutDownComplete are sent only when all
volumes are shutdown. (Not one for every volume.)

Change-Id: I6af521ee8285ca581efac7d3c5f013dfbff3ee30