linux-wandboard

[IB] umad: fix hot remove of IB devices

Fix hotplug of devices for ib_umad module: when a device goes away,
kill off all MAD agents for open files associated with that device,
and make sure that the device is not touched again after ib_umad
returns from its remove_one function.

Signed-off-by: Roland Dreier <rolandd@cisco.com>