Remove unnecessary checks in configure.ac.
Remove unnecessary checks in configure.ac.

Distrotech/audiofile,eriser/audiofile,fabzzap/audiofile,eriser/audiofile,mpruett/audiofile,mpruett/audiofile,Distrotech/audiofile,Distrotech/audiofile,eriser/audiofile,fabzzap/audiofile,mpruett/audiofile,fabzzap/audiofile