I agree that as long as there's no swelling or heat radiating off of it it should be fine to heal on it's own. Don't be surprised if it heals slowly though, and don't pick at any scabbing, as ears bleed easily. A while ago my dogs were rough housing and one of them got an ear nick that looked similar to yours. It scabbed over without issue, then she fell into our pond while chasing ducks and the scab came off and the darn thing started bleeding again and wouldn't stop, even though the wound was weeks old by that point. I ended up using gauze and vet wrap to wrap her ear down against her head to stop the bleeding, then once it scabbed over again, we were very careful to not let the scab get wet or torn off. It took months to completely heal up, and there's still a little residual rough patch where it was.