SCSI Fix oops with faulty DVD

There's a refcounting problem on the error leg of sr_open().
fix it.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/sr.c

@@ -544,7 +544,6 @@ static int sr_open(struct cdrom_device_info *cdi, int purpose)
 	return 0;
 
 error_out:
-	scsi_cd_put(cd);
 	return retval;	
 }