'stub' cannot be non NULL, remove test.

'stub' cannot be non NULL, remove test.

13429 cleanup:
13430        cancel_refresh(zone);

	CID 1452702 (#1 of 1): Dereference before null check (REVERSE_INULL)
	check_after_deref: Null-checking stub suggests that it may
	be null, but it has already been dereferenced on all paths
	leading to the check.

13431        if (stub != NULL) {
13432                stub->magic = 0;