[S390] fix subsystem removal fallout

This patch fixes compilation on s390 after the removal of
struct subsystem.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/hypfs/inode.c

@@ -477,7 +477,7 @@ static int __init hypfs_init(void)
 			goto fail_diag;
 		}
 	}
-	kset_set_kset_s(&s390_subsys, hypervisor_subsys);
+	kobj_set_kset_s(&s390_subsys, hypervisor_subsys);
 	rc = subsystem_register(&s390_subsys);
 	if (rc)
 		goto fail_sysfs;