Staging: hv: Fix vmbus load hang caused by faulty data packing

Fix vmbus load hang caused by wrong data packing.

Signed-off-by: Hank <Janssen&lt;hjanssen@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>