Remove unnecessary use crate::sess::ParseSess;.

Author: Centril

src/libsyntax/ext/expand.rs

@@ -15,7 +15,6 @@ use crate::parse::token;
 use crate::parse::parser::Parser;
 use crate::print::pprust;
 use crate::ptr::P;
-use crate::sess::ParseSess;
 use crate::symbol::{sym, Symbol};
 use crate::tokenstream::{TokenStream, TokenTree};
 use crate::visit::Visitor;