s390/dasd: remove cast for kzalloc return value

remove cast for kzalloc return value.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/block/dasd_devmap.c

@@ -410,8 +410,7 @@ dasd_add_busid(const char *bus_id, int features)
 	struct dasd_devmap *devmap, *new, *tmp;
 	int hash;
 
-	new = (struct dasd_devmap *)
-		kzalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
+	new = kzalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
 	if (!new)
 		return ERR_PTR(-ENOMEM);
 	spin_lock(&dasd_devmap_lock);