load.c: call mrb_top_run() from mrb_load_proc(); fix #5504

So that the function behave consistently with `mrb_load_proc()`.

src/load.c

@@ -683,7 +683,7 @@ mrb_load_irep_buf(mrb_state *mrb, const void *buf, size_t bufsize)
 MRB_API mrb_value
 mrb_load_proc(mrb_state *mrb, const struct RProc *proc)
 {
-  return mrb_vm_run(mrb, proc, mrb_top_self(mrb), 0);
+  return mrb_top_run(mrb, proc, mrb_top_self(mrb), 0);
 }
 
 #ifndef MRB_NO_STDIO