avcodec/bsf/dts2pts: don't zero the node buffers when allocating them

It's unnecessary as the entire struct is written to immediately after it's
allocated.
Restores the behavior prior to fec6a8df31.

Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/bsf/dts2pts.c

@@ -396,7 +396,8 @@ static int dts2pts_init(AVBSFContext *ctx)
     if (!s->fifo)
         return AVERROR(ENOMEM);
 
-    s->node_pool = ff_refstruct_pool_alloc(sizeof(DTS2PTSNode), 0);
+    s->node_pool = ff_refstruct_pool_alloc(sizeof(DTS2PTSNode),
+                                           FF_REFSTRUCT_POOL_FLAG_NO_ZEROING);
 
     if (!s->node_pool)
         return AVERROR(ENOMEM);