nvme-pci: queue creation fixes

We've been ignoring NVMe error status on queue creations. Fortunately they
are uncommon, but we should handle these anyway. This patch adds checks
for the a positive error return value that indicates an NVMe status.

If we do see a negative return, the controller isn't usable, so this
patch returns immediately in since we can't unwind that failure.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>