enable write_data for atom styles with bonus data

src/atom_vec.cpp

@@ -2304,6 +2304,16 @@ void AtomVec::write_improper(FILE *fp, int n, tagint **buf, int index)
   }
 }
 
+/* ----------------------------------------------------------------------
+   return size_data_bonus
+   only AtomVecHybrid overrides this, so it can select which bonus data via flag
+------------------------------------------------------------------------- */
+
+int AtomVec::size_data_bonus_query(int /*flag*/)
+{
+  return size_data_bonus;
+}
+
 /* ----------------------------------------------------------------------
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */