Fix dogfood lint error

Author: Vinh Tran

src/driver.rs

@@ -26,6 +26,7 @@ use std::fs::read_to_string;
 use std::ops::Deref;
 use std::path::Path;
 use std::process::exit;
+use std::string::ToString;
 
 use anstream::println;
 
@@ -190,24 +191,24 @@ pub fn main() {
     exit(rustc_driver::catch_with_exit_code(move || {
         let mut orig_args: Vec<String> = env::args().collect();
 
-        let has_sysroot_arg = |args: &mut Vec<String>| {
-            if arg_value(&args, "--sysroot", |_| true).is_some() {
+        let has_sysroot_arg = |args: &mut [String]| -> bool {
+            if arg_value(args, "--sysroot", |_| true).is_some() {
                 return true;
             }
             // https://doc.rust-lang.org/rustc/command-line-arguments.html#path-load-command-line-flags-from-a-path
-            // Beside checking for existence of `--sysroot` from the args on the command line, we need to
+            // Beside checking for existence of `--sysroot` on the command line, we need to
             // check for the arg files that are prefixed with @ as well to be consistent with rustc
             for arg in args.iter() {
-                if let Some(arg_file_path) = arg.strip_prefix("@") {
+                if let Some(arg_file_path) = arg.strip_prefix('@') {
                     if let Ok(arg_file) = read_to_string(arg_file_path) {
-                        let split_arg_file: Vec<String> = arg_file.lines().map(|s| s.to_string()).collect();
+                        let split_arg_file: Vec<String> = arg_file.lines().map(ToString::to_string).collect();
                         if arg_value(&split_arg_file, "--sysroot", |_| true).is_some() {
                             return true;
                         }
                     }
                 }
             }
-            return false;
+            false
         };
 
         let sys_root_env = std::env::var("SYSROOT").ok();