net/rds: Don't sleep inside rds_ib_conn_path_shutdown

In the Linux kernel, the following vulnerability has been resolved: net/rds: Don't sleep inside rds_ib_conn_path_shutdown New rds rdma self tests exposed a hang when tearing down the ib network configs. This is caused by the shutdown worker thread sleeping on the wait_event call, which blocks other work items in the queue. Fix this by changing wait_event to wait_event timeout, and looping until the wait check succeeds.

Where it's fixed