flexframesync/benchmark: cleaning up to use internal callback
flexframesync/benchmark: cleaning up to use internal callback

jgaeddert/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp,jgaeddert/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp,wangning223/liquid-dsp,jgaeddert/liquid-dsp,wangning223/liquid-dsp,wangning223/liquid-dsp