nvme: quiet user passthrough command errors

The driver is spamming the kernel logs for entirely harmless errors from
user space submitting unsupported commands. Just silence the errors.
The application has direct access to command status, so there's no need
to log these.

And since every passthrough command now uses the quiet flag, move the
setting to the common initializer.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Alan Adamson <alan.adamson@oracle.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Tested-by: Alan Adamson <alan.adamson@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>