Commit 15b2260b ("block/nvme: Trace controller capabilities")
misunderstood the doorbell stride value from the datasheet, use
the correct one. The 'doorbell_scale' variable used few lines
later is correct.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210127212137.3482291-2-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>