Staging: hv: Change the signature for vmbus_cleanup()

As part of geting rid of hv_driver object from
vmbus_driver_context, change the signature of
vmbus_cleanup() function. Note that while
vmbus_cleanup() was passed a pointer to hv_driver,
this argument was unused.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Mike Sterling <mike.sterling@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>