Reshuffle response handling in scsi_mode_sense() to make the code easier to
follow.

[mkp: fix build]

Link: https://lore.kernel.org/r/20210427083046.31620-5-hare@suse.deSuggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>