Fixing a bug in BaseIIRFilterReader.
Fixing a bug in BaseIIRFilterReader.

It crashed when the coefficient length is zero.

neXyon/audaspace,DethonUSAL/audaspace,neXyon/audaspace,audaspace/audaspace,audaspace/audaspace,neXyon/audaspace,DethonUSAL/audaspace,DethonUSAL/audaspace,audaspace/audaspace