[PATCH 1/3] nvme-fabrics: introduce existing_ctrl operation

[Christoph Hellwig]

> +	if (ops->existing_ctrl) {
> +		if (!opts->duplicate_connect && ops->existing_ctrl(opts)) {

Nitpick, but the logic would read easier at least to me as:

	if (!opts->duplicate_connect &&
            ops->existing_ctrl && ops->existing_ctrl(opts)) {

I can fix this up if we get some more positive reviews and this gets
applied.