cleanup unused variables

#define LFE_PLC_DSF        ( 48000 / LFE_PLC_FS )

#define LFE_PLC_LPCORD     ( 20 )

#define LFE_PLC_MAXITER    ( 10 )

#define POW_THR            ( 1.0e-8f )

#define LFE_PLC_RECLEN_48K ( ( IVAS_LFE_NUM_COEFFS_IN_SUBGRP + 1 ) * L_FRAME48k / IVAS_LFE_NUM_COEFFS_IN_SUBGRP + LFE_PLC_FDEL )

#define LFE_PLC_RECLEN     ( ( LFE_PLC_RECLEN_48K / LFE_PLC_DSF ) )

#define LFE_PLC_MUTE_THR   ( 10 )

#ifdef NONE_BE_FIX_816_LFE_PLC_FLOAT

#define LFE_PLC_BURST_ATT  ( powf( powf( 10.0f, -3.0f / 20.0f ), 1.0f / ( LFE_PLC_FS * 20 / 1000 ) ) ) /* attenuate 3dB per frame starting with 10th consecutive loss */

#define MAX_LEN_LP 960

#define EPS_STOP 1e-5f

#else

#define LFE_PLC_BURST_ATT  ( pow( pow( 10.0, -3.0 / 20.0 ), 1.0 / ( LFE_PLC_FS * 0.02 ) ) ) /* attenuate 3dB per frame starting with 10th consecutive loss */