Fix one more issue

Signed-off-by: Tej Chajed <[email protected]>

fly/src/printer.rs

@@ -228,7 +228,7 @@ fn signature(sig: &Signature) -> String {
         .sorts
         .iter()
         // end with trailing newline if there are any sorts
-        .map(|s| format!("sort {}\n", s))
+        .map(|s| format!("sort {s}\n"))
         .collect::<Vec<_>>()
         .join("");
     let relations = sig