lstopo/draw: improve the removal of space between boxes for PUs

Don't propagate this removal to memory children
(if we ever have an object with PU normal children and multiple NUMA nodes,
 e.g. lstopo -i "pack:1 [numa] [numa] pu:4").

This further improves commit 200a7b7
but brings back the vertical space between PUs and a parent cache.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

utils/lstopo/lstopo-draw.c

@@ -487,6 +487,7 @@ place_children(struct lstopo_output *loutput, hwloc_obj_t parent,
   enum lstopo_orient_e orient = loutput->force_orient[parent->type];
   unsigned border = loutput->gridsize;
   unsigned separator = loutput->gridsize;
+  unsigned normal_children_separator = separator;
   unsigned totwidth = plud->width, totheight = plud->height;
   unsigned children_width = 0, children_height = 0;
   unsigned above_children_width, above_children_height;
@@ -524,11 +525,11 @@ place_children(struct lstopo_output *loutput, hwloc_obj_t parent,
 
   /* no separator between PUs */
   if ((unsigned)parent->depth == loutput->depth-2)
-    separator = 0;
+    normal_children_separator = 0;
 
   /* place non-memory children */
   if (parent->arity + parent->io_arity + parent->misc_arity)
-    place__children(loutput, parent, plud->children.kinds, &orient, 0, separator, &children_width, &children_height);
+    place__children(loutput, parent, plud->children.kinds, &orient, 0, normal_children_separator, &children_width, &children_height);
 
   /* place memory children */
   if (plud->above_children.kinds) {