Avoid redundant closures when calling methods

src/main.rs

@@ -62,7 +62,7 @@ fn main() {
     }
 
     let args: Vec<_> = env::args_os().skip(1).collect();
-    match Options::parse(args.iter().map(|e| e.as_ref()), &LiveVars) {
+    match Options::parse(args.iter().map(std::convert::AsRef::as_ref), &LiveVars) {
         OptionsResult::Ok(options, mut input_paths) => {
 
             // List the current directory by default.