fix clippy

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

Diff for: crates/rustc_codegen_c/src/builder.rs

@@ -3,7 +3,6 @@
 use std::ops::Deref;
 
 use rustc_abi::{HasDataLayout, TargetDataLayout};
-use rustc_codegen_c_ast::expr::{CExpr, CValue};
 use rustc_codegen_c_ast::func::CFunc;
 use rustc_codegen_ssa::traits::{BackendTypes, BuilderMethods, HasCodegen};
 use rustc_middle::ty::layout::{

Diff for: crates/rustc_codegen_c_ast/src/ty.rs

@@ -237,7 +237,7 @@ pub(crate) fn print_declarator(mut ty: CTy, val: Option<CValue>, ctx: &mut Print
                     ctx.word("*");
                 }
                 DeclaratorPart::ArrayDim(dim) => {
-                    ctx.word(format!("[{}]", dim.to_string()));
+                    ctx.word(format!("[{}]", dim));
                 }
                 DeclaratorPart::Lp => ctx.word("("),
                 DeclaratorPart::Rp => ctx.word(")"),