scsi: ufs: Introduce the function ufshcd_execute_start_stop()

Open-code scsi_execute() because a later patch will modify scmd->flags and
because scsi_execute() does not support setting scmd->flags. No
functionality is changed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221018202958.1902564-10-bvanassche@acm.org


Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>