Fix iLBC compiler warnings

codecs/ilbc/FrameClassify.c

codecs/ilbc/LPCdecode.c

codecs/ilbc/LPCencode.c

codecs/ilbc/StateConstructW.c

codecs/ilbc/StateSearchW.c

codecs/ilbc/anaFilter.c

codecs/ilbc/createCB.c

codecs/ilbc/doCPLC.c

codecs/ilbc/enhancer.c

codecs/ilbc/filter.c

codecs/ilbc/gainquant.c

codecs/ilbc/getCBvec.c

codecs/ilbc/helpfun.c

codecs/ilbc/hpInput.c

codecs/ilbc/hpOutput.c

codecs/ilbc/iCBConstruct.c

codecs/ilbc/iCBSearch.c

codecs/ilbc/iLBC_decode.c

codecs/ilbc/iLBC_encode.c

codecs/ilbc/lsf.c