scsi: Implement sr_printk()

Update the sr driver to use dev_printk() variants instead of
plain printk(); this will prefix logging messages with the
appropriate device.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --cc drivers/scsi/sr.c
Simple merge

diff --cc drivers/scsi/sr.h
Simple merge

diff --cc drivers/scsi/sr_ioctl.c
Simple merge

diff --cc drivers/scsi/sr_vendor.c
Simple merge