Fix syntax errors in the antiAliasFilterNode initialization.
Fix syntax errors in the antiAliasFilterNode initialization.

This fixes the surprising lowpass look of the webaudio demo.  The
default cutoff frequency of a BiquadFilterNode appears to be 350Hz,
which is what was in use before this change.  The cutoff is now
correctly set to 8000 Hz.

google/carfac,google/carfac,google/carfac,google/carfac,google/carfac