scsi: sd: Use separate buf for START_STOP in sd_spinup_disk()

scsi: sd: Use separate buf for START_STOP in sd_spinup_disk()

We currently reuse the cmd buffer for the TUR and START_STOP commands
which requires us to reset the buffer when retrying. This has us use
separate buffers for the 2 commands so we can make them const and I think
it makes it easier to handle for retries but does not add too much extra to
the stack use.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-5-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>