Fix summing of losses
Fix summing of losses

`total_loss` was being added to itself at least once in the sum, now it
is excluded.

PavlosMelissinos/densecap,jcjohnson/densecap,PavlosMelissinos/densecap,jcjohnson/densecap,jcjohnson/densecap,jcjohnson/densecap,PavlosMelissinos/densecap,PavlosMelissinos/densecap