[S390] dasd: optimize cpu usage in goodcase

remove unnecessary dbf call, remove string operations for magic

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_eer.c b/drivers/s390/block/dasd_eer.c
index c24c8c3..6bd2bd5 100644
--- a/drivers/s390/block/dasd_eer.c
+++ b/drivers/s390/block/dasd_eer.c
@@ -464,7 +464,7 @@
 	if (!device->discipline || strcmp(device->discipline->name, "ECKD"))
 		return -EPERM;	/* FIXME: -EMEDIUMTYPE ? */
 
-	cqr = dasd_kmalloc_request("ECKD", 1 /* SNSS */,
+	cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* SNSS */,
 				   SNSS_DATA_SIZE, device);
 	if (IS_ERR(cqr))
 		return -ENOMEM;