[S390] tape: fix dbf usage

Get rid of the format string "%s" usage with volatile strings
to prevent use after free errors in the s390dbf.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/tape_core.c

@@ -1077,15 +1077,14 @@ __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
 		/* FIXME: What to do with the request? */
 		switch (PTR_ERR(irb)) {
 			case -ETIMEDOUT:
-				DBF_LH(1, "(%s): Request timed out\n",
-					dev_name(&cdev->dev));
+				DBF_LH(1, "(%08x): Request timed out\n",
+				       device->cdev_id);
 			case -EIO:
 				__tape_end_request(device, request, -EIO);
 				break;
 			default:
-				DBF_LH(1, "(%s): Unexpected i/o error %li\n",
-					dev_name(&cdev->dev),
-					PTR_ERR(irb));
+				DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
+				       device->cdev_id,	PTR_ERR(irb));
 		}
 		return;
 	}

drivers/s390/char/tape_std.c

@@ -47,8 +47,8 @@ tape_std_assign_timeout(unsigned long data)
 			device->cdev_id);
 	rc = tape_cancel_io(device, request);
 	if(rc)
-		DBF_EVENT(3, "(%s): Assign timeout: Cancel failed with rc = %i\n",
-			dev_name(&device->cdev->dev), rc);
+		DBF_EVENT(3, "(%08x): Assign timeout: Cancel failed with rc = "
+			  "%i\n", device->cdev_id, rc);
 }
 
 int