af_earwax: remove unused pointer value

Fixes CID703849
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/af_earwax.c

@@ -141,7 +141,7 @@ static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
 
     // process current input
     endin = in + insamples->audio->nb_samples * 2 - NUMTAPS;
-    out   = scalarproduct(in, endin, out);
+    scalarproduct(in, endin, out);
 
     // save part of input for next round
     memcpy(taps, endin, NUMTAPS * sizeof(*taps));