dasd: fix list_del corruption during format

If I/O errors occur during format a kernel panic with a list_del
corruption may occur.

Stop error recovery procedure after an erp action was taken.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd.c

@@ -2307,8 +2307,12 @@ static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
 
 	rc = 0;
 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
-		if (__dasd_sleep_on_erp(cqr))
+		if (__dasd_sleep_on_erp(cqr)) {
+			if (!cqr->status == DASD_CQR_TERMINATED &&
+			    !cqr->status == DASD_CQR_NEED_ERP)
+				break;
 			rc = 1;
+		}
 	}
 	if (rc)
 		goto retry;