aac: remove now-unused redundant array

This commit removes the array which was made redundant with
the last commit. The current prediction system gets the
quantization error directly (and without the single-frame delay)
in the search_for_pred function.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

libavcodec/aac.h

@@ -259,7 +259,6 @@ typedef struct SingleChannelElement {
     DECLARE_ALIGNED(32, INTFLOAT, saved)[1536];     ///< overlap
     DECLARE_ALIGNED(32, INTFLOAT, ret_buf)[2048];   ///< PCM output buffer
     DECLARE_ALIGNED(16, INTFLOAT, ltp_state)[3072]; ///< time signal for LTP
-    DECLARE_ALIGNED(32, AAC_FLOAT, pqcoeffs)[1024]; ///< quantization error of coefs (used by encoder)
     DECLARE_ALIGNED(32, AAC_FLOAT, prcoeffs)[1024]; ///< Main prediction coefs (used by encoder)
     PredictorState predictor_state[MAX_PREDICTORS];
     INTFLOAT *ret;                                  ///< PCM output