Oggenc channel integer overflow

I discovered an integer overflow issue in oggenc, related to the number of channels in the input WAV file. The issue triggers an out-of-bounds memory access which causes oggenc to crash here (audio.c) :

576 memcpy(wav->channel_permute, wav_permute_matrix[wav->channels-1], 
577	                    sizeof(int) * wav->channels);

Tests were performed using vorbis-tools 1.4.0