encode.c:950:9⚠️ variable noisy_sbs set but not used
encode.c:990:9⚠️ variable noisy_sbs set but not used
musicin.c:176:9⚠️ variable mono set but not used
musicin.c:175:9⚠️ variable stereo set but not used
Once the unused variables were removed it was noticed that the return values
of two functions were always ignored - these could be changed to void().
