Remove unnecessary assignment, found by CSA.

Originally committed as revision 18617 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/aac.c

@@ -1616,7 +1616,7 @@ static int aac_decode_frame(AVCodecContext * avccontext, void * data, int * data
     init_get_bits(&gb, buf, buf_size*8);
 
     if (show_bits(&gb, 12) == 0xfff) {
-        if ((err = parse_adts_frame_header(ac, &gb)) < 0) {
+        if (parse_adts_frame_header(ac, &gb) < 0) {
             av_log(avccontext, AV_LOG_ERROR, "Error decoding AAC frame header.\n");
             return -1;
         }