printf usage in performance critical functions #656

We should avoid variadic printf calls in important functions that get called a lot. Even if the branch does not get taken that invokes the printf, the performance will be degraded due to lower occupancy (and maybe other things?).

An example is the printfs in https://github.com/lanl/singularity-eos/blob/main/singularity-utils/singularity-utils/root-finding-1d/root_finding.hpp