GPencil: Fix Noise Modifier Randomize Panel disabled

Fix regression introduced in rB34b213d60472

Reviewed By: antoniov

Differential Revision: https://developer.blender.org/D12398

source/blender/gpencil_modifiers/intern/MOD_gpencilnoise.c

@@ -324,7 +324,7 @@ static void random_panel_draw(const bContext *UNUSED(C), Panel *panel)
 
   uiLayoutSetPropSep(layout, true);
 
-  uiLayoutSetActive(layout, RNA_boolean_get(ptr, "random"));
+  uiLayoutSetActive(layout, RNA_boolean_get(ptr, "use_random"));
 
   uiItemR(layout, ptr, "step", 0, NULL, ICON_NONE);
 }