RDMA/ipoib: Drain RCU callbacks during module teardown

In the Linux kernel, the following vulnerability has been resolved: RDMA/ipoib: Drain RCU callbacks during module teardown IPoIB reclamation completions can be signaled from inside an RCU callback. Teardown can wake before the callback returns and unload ib_ipoib while its code is still executing. Client registration failure can also remove already-added devices and queue callbacks. Wait after client and workqueue teardown.

Where it's fixed