scsi: introduce sdev_prefix_printk()

Like scmd_printk(), but the device name is passed in as
a string. Can be used by eg ULDs which do not have access
to the scsi_cmnd structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/sr.h b/drivers/scsi/sr.h
index 1d1f6f4..1de3371 100644
--- a/drivers/scsi/sr.h
+++ b/drivers/scsi/sr.h
@@ -57,8 +57,7 @@
 } Scsi_CD;
 
 #define sr_printk(prefix, cd, fmt, a...) \
-	sdev_printk(prefix, (cd)->device, "[%s] " fmt, \
-		    (cd)->cdi.name, ##a)
+	sdev_prefix_printk(prefix, (cd)->device, (cd)->cdi.name, fmt, ##a)
 
 int sr_do_ioctl(Scsi_CD *, struct packet_command *);