avcodec/cook: use av_freep()

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/cook.c

@@ -228,7 +228,7 @@ static av_cold int init_cook_mlt(COOKContext *q)
 
     /* Initialize the MDCT. */
     if ((ret = ff_mdct_init(&q->mdct_ctx, av_log2(mlt_size) + 1, 1, 1.0 / 32768.0))) {
-        av_free(q->mlt_window);
+        av_freep(&q->mlt_window);
         return ret;
     }
     av_log(q->avctx, AV_LOG_DEBUG, "MDCT initialized, order = %d.\n",
@@ -302,8 +302,8 @@ static av_cold int cook_decode_close(AVCodecContext *avctx)
     av_log(avctx, AV_LOG_DEBUG, "Deallocating memory.\n");
 
     /* Free allocated memory buffers. */
-    av_free(q->mlt_window);
-    av_free(q->decoded_bytes_buffer);
+    av_freep(&q->mlt_window);
+    av_freep(&q->decoded_bytes_buffer);
 
     /* Free the transform. */
     ff_mdct_end(&q->mdct_ctx);