fop(1): closure fix

src/fop.rs

@@ -93,7 +93,7 @@ fn main() {
 		drop(child_stdin);
 	}
 
-	let output = spawned.wait_with_output().unwrap_or_else(|| {
+	let output = spawned.wait_with_output().unwrap_or_else(|_| {
 		eprintln!("{}: {}: Command has no output.",
 			argv[0],
 			argv[command_arg]