[S390] cio: Log the response from the unit check handler

Log the response from the unit check handler which triggers further
cio internal i/o processing.

Signed-off-by: Michael Ernst <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/cio/ccwreq.c

···
 		/* Ask the driver what to do */
 		if (cdev->drv && cdev->drv->uc_handler) {
 			todo = cdev->drv->uc_handler(cdev, lcirb);
+			CIO_TRACE_EVENT(2, "uc_response");
+			CIO_HEX_EVENT(2, &todo, sizeof(todo));
 			switch (todo) {
 			case UC_TODO_RETRY:
 				return IO_STATUS_ERROR;