add missing call in zig fmt to commit results to disk

src-self-hosted/main.zig

@@ -741,6 +741,7 @@ fn fmtMain(allocator: &mem.Allocator, file_paths: []const []const u8) !void {
         defer baf.destroy();
 
         try parser.renderSource(baf.stream(), tree.root_node);
+        try baf.finish();
     }
 }