Revert "Update rustc-perf submodule before running tidy"

This reverts commit faac70b.

src/bootstrap/src/core/build_steps/test.rs

@@ -1101,8 +1101,6 @@ impl Step for Tidy {
     /// Once tidy passes, this step also runs `fmt --check` if tests are being run
     /// for the `dev` or `nightly` channels.
     fn run(self, builder: &Builder<'_>) {
-        builder.build.update_submodule(Path::new("src/tools/rustc-perf"));
-
         let mut cmd = builder.tool_cmd(Tool::Tidy);
         cmd.arg(&builder.src);
         cmd.arg(&builder.initial_cargo);