Staging: hv: vmbus_driver cannot be unloaded; cleanup accordingly

Staging: hv: vmbus_driver cannot be unloaded; cleanup accordingly

The vmbus driver cannot be unloaded; the windows host does not
permit this: A) All guest resources given to the host cannot
be recovered and B) Windows host does not permit reloading the
vmbus_driver without re-booting the guest. Both these issues
are host related. Acknowledge this reality and cleanup the
vmbus driver accordingly. Note that, ideally we will want to handle
the root device through the Hyper-V block driver. In this case
unloading the vmbus driver will not be possible because of the
dependency issues.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>