Remove now-unneeded prefix fixing code.
Remove now-unneeded prefix fixing code.

With the root directory under the library's control, we do not need
to do defensive prefix adjustments.

legrosbuffle/kythe,benjyw/kythe,bowlofstew/kythe,bzz/kythe,benjyw/kythe,legrosbuffle/kythe,bowlofstew/kythe,bzz/kythe,legrosbuffle/kythe,kythe/kythe,Acidburn0zzz/kythe,kidaa/kythe,bowlofstew/kythe,kythe/kythe,benjyw/kythe,Acidburn0zzz/kythe,kidaa/kythe,Acidburn0zzz/kythe,kidaa/kythe,kidaa/kythe,legrosbuffle/kythe,benjyw/kythe,bowlofstew/kythe,Acidburn0zzz/kythe,bowlofstew/kythe,bowlofstew/kythe,bzz/kythe,bowlofstew/kythe,benjyw/kythe,legrosbuffle/kythe,bowlofstew/kythe,bzz/kythe,kidaa/kythe,bzz/kythe,legrosbuffle/kythe,Acidburn0zzz/kythe,benjyw/kythe,kidaa/kythe,bzz/kythe,Acidburn0zzz/kythe,benjyw/kythe,legrosbuffle/kythe,bowlofstew/kythe,kythe/kythe,kidaa/kythe,bzz/kythe,Acidburn0zzz/kythe,kythe/kythe,kythe/kythe,bowlofstew/kythe,bzz/kythe,kythe/kythe,kythe/kythe,bzz/kythe,Acidburn0zzz/kythe,bzz/kythe,kidaa/kythe,benjyw/kythe,Acidburn0zzz/kythe,kythe/kythe,legrosbuffle/kythe,benjyw/kythe,kythe/kythe,benjyw/kythe,legrosbuffle/kythe,legrosbuffle/kythe,kidaa/kythe,bowlofstew/kythe,benjyw/kythe,kythe/kythe,kythe/kythe,benjyw/kythe,bzz/kythe,legrosbuffle/kythe,bzz/kythe