scsi: move the writeable field from struct scsi_device to struct scsi_cd

We currently set the field in common code based on the device type,
but then only use it in the cdrom driver which also overrides the
value previously set in the generic code.

Just leave this entirely to the CDROM driver to make everyones life
simpler.

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

drivers/scsi/sr.h

@@ -36,6 +36,7 @@ typedef struct scsi_cd {
 	struct scsi_device *device;
 	unsigned int vendor;	/* vendor code, see sr_vendor.c         */
 	unsigned long ms_offset;	/* for reading multisession-CD's        */
+	unsigned writeable : 1;
 	unsigned use:1;		/* is this device still supportable     */
 	unsigned xa_flag:1;	/* CD has XA sectors ? */
 	unsigned readcd_known:1;	/* drive supports READ_CD (0xbe) */