Preparation for polling support for fabrics. Polling support
means that our completion queues are not generating any interrupts
which means we need to poll for the nvmf io queue connect as well.

Reviewed by Steve Wise <swise@opengridcomputing.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>