Remove compile-time prints

[phoe]

https://github.com/sharplispers/cl-jpeg/blob/ec557038128df6895fbfb743bfe8faf8ec2534af/jpeg.lisp#L317

https://github.com/sharplispers/cl-jpeg/blob/ec557038128df6895fbfb743bfe8faf8ec2534af/jpeg.lisp#L360

This optimization is instantaneous enough to be unnoticeable compile-time-wise, and the printouts generate unnecessary noise while the system is compiled.