Switch to scsi_execute_req_flags() and scsi_get_vpd_page() instead of
open-coding it. Using scsi_execute_req_flags() will set REQ_QUIET and
REQ_PREEMPT, but this is okay as we're evaluating the errors anyway and
should be able to send the command even if the device is quiesced.
Signed-off-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>