The Completion Queue Command Identifier is a 16-bit value,
so nvme_submit_command() is unlikely to work on big-endian
hosts, as the relevant bits are truncated.
Fix by using the correct byte-swap function.

Fixes: bdd6a90a ("block: Add VFIO based NVMe driver")
Reported-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20201029093306.1063879-25-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>