Fix T91458: Displaying dope-sheet with sequencer keyframes crashes

Error in e6194e7357.

source/blender/editors/animation/anim_deps.c

@@ -217,8 +217,6 @@ static void animchan_sync_fcurve_scene(bAnimListElem *ale)
   /* Check if this strip is selected. */
   Editing *ed = SEQ_editing_get(scene);
   seq = SEQ_get_sequence_by_name(ed->seqbasep, seq_name, false);
-  MEM_freeN(seq_name);
-
   if (seq == NULL) {
     return;
   }