nvme/pcie: Dequeue request from outstanding list before calling completion

Each request has a callback context as cb_arg, and the callback to
nvme_complete_request() for the completed request may reuse the context
to the new request.

On the other hand, nvme_pcie_qpair_complete_tracker() dequeues tr from
pqpair->outstanding_tr after calling nvme_complete_request() for the
request pointed by tr.

Hence while nvme_complete_request() is executed, pqpair->outstanding_tr
may have two requests which has the same callback context, the
completed request and the new submitted request.

The upcoming patch will search all requests whose cb_arg matches to
abort them. In the above case, the search may find two requests by
mistake.

To avoid such error, change nvme_pcie_qpair_complete_tracker() to
dequeue tr from pqpair->outstanding_tr before calling nvme_complete_request().

Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Ie9efc200d06d02d8ee2be3cb8e9fd64591bc210d
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/2861


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Michael Haeuptle <michaelhaeuptle@gmail.com>