Remove buffer size assertion in Synth::construct
Remove buffer size assertion in Synth::construct

Correct buffer size is not really necessary at this point and should be handled
explicitly, because the audio driver is free to use any buffer size.

samplecount/methcla,samplecount/methcla,samplecount/methcla,samplecount/methcla,samplecount/methcla,samplecount/methcla