Staging: hv: Get rid of lun_id from struct hv_storvsc_request

Staging: hv: Get rid of lun_id from struct hv_storvsc_request

In preparation for consolidating all I/O request state, get rid of the
lun_id field from struct hv_storvsc_request and instead use the
equivalent  state in struct vmscsi_request - lun field.

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>