aac_adtstoasc_bsf: Check extradata memory allocation

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/aac_adtstoasc_bsf.c

@@ -89,6 +89,8 @@ static int aac_adtstoasc_filter(AVBitStreamFilterContext *bsfc,
         }
         avctx->extradata_size = 2 + pce_size;
         avctx->extradata = av_mallocz(avctx->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
+        if (!avctx->extradata)
+            return AVERROR(ENOMEM);
 
         init_put_bits(&pb, avctx->extradata, avctx->extradata_size);
         put_bits(&pb, 5, hdr.object_type);