vf_deinterlace_vaapi: Mark as hwframe-aware

Commits ade370a4 and e3fb74f7 were reordered while merging, so this
change got lost.

libavfilter/vf_deinterlace_vaapi.c

@@ -631,4 +631,5 @@ AVFilter ff_vf_deinterlace_vaapi = {
     .inputs         = deint_vaapi_inputs,
     .outputs        = deint_vaapi_outputs,
     .priv_class     = &deint_vaapi_class,
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
 };