Staging: hv: Cleanup vmbus_match()

In preparation for getting rid of the priv element from struct hv_driver,
cleanup vmbus_match - the setting of the drv field in struct hv_device
is not needed.

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>