In the ns__client_put_cb() callback function the 'client->manager'
pointer is guaranteed to be non-NULL, because in ns__client_request(),
before setting up the callback, the ns__client_setup() function is
called for the 'client', which makes sure that 'client->manager' is set.
Removing the NULL-check resolves the following static analyzer warning:
/lib/ns/client.c: 1675 in ns__client_put_cb()
1669 dns_message_puttemprdataset(client->message, &client->opt);
1670 }
1671 client_extendederror_reset(client);
1672
1673 dns_message_detach(&client->message);
1674
>>> CID 465168: Null pointer dereferences (REVERSE_INULL)
>>> Null-checking "client->manager" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
1675 if (client->manager != NULL) {
1676 ns_clientmgr_detach(&client->manager);
1677 }
1678
1679 /*
1680 * Detaching the task must be done after unlinking from
2a57c12922