remove stray comment

Author: CleanCut

compiler/rustc_monomorphize/src/errors.rs

@@ -3,7 +3,6 @@ use std::path::PathBuf;
 use rustc_errors::ErrorGuaranteed;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic};
 use rustc_session::SessionDiagnostic;
-// use rustc_session::SessionDiagnostic;
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]