Fix mismerge in OFED update

[rstone]

Summary

When OFED was upgraded to Linux v4.9, a bunch of Linux-specific
netlink changes were dropped. Unfortunately, there was a mismerge
in this process and as a result ib_sa_cancel_query() would fail to
cancel an outstanding MAD.

This was causing rdma_destroy_id() to hang indefinitely waiting
for the MAD to complete and release the final reference.

Sponsored by: Dell Inc.

[• hselasky]

I'll have a look at this tomorrow.

Thank you!

--HPS

[• hselasky]

Targetting a review for Monday.

[• hselasky]

Looks good.

Please don't forget to MFC to 13-, 12- and 11 -stable.

--HPS