butterflies: add explicit brackets

src/modules/butterflies/butterflies_overlays.c

@@ -49,8 +49,8 @@ enum action_status bf_grid_overlay_update(const struct cats_configuration *conf,
                                 cells_resource_ok += 1;
                         }
 
-                        if (data->info_layer[row][col] & BF_CELL_HABITAT_OK &&
-                            data->info_layer[row][col] & BF_CELL_RESOURCE_AVAILABLE) {
+                        if ((data->info_layer[row][col] & BF_CELL_HABITAT_OK) &&
+                                (data->info_layer[row][col] & BF_CELL_RESOURCE_AVAILABLE)) {
                                 data->info_layer[row][col] |= BF_CELL_VALID_DISPERSAL_TARGET;
                                 cells_habitat_and_resource_ok += 1;