Merge pull request RustPython#4325 from harupy/4324-follow-up

A follow-up for RustPython#4324

Author: DimitrisJim

compiler/parser/src/string.rs

@@ -81,16 +81,18 @@ pub fn parse_strings(
         deduped.push(take_current(&mut current));
     }
 
-    let node = if has_fstring {
-        ExprKind::JoinedStr { values: deduped }
+    Ok(if has_fstring {
+        Expr::new(
+            initial_start,
+            last_end,
+            ExprKind::JoinedStr { values: deduped },
+        )
     } else {
         deduped
             .into_iter()
             .exactly_one()
             .expect("String must be concatenated to a single element.")
-            .node
-    };
-    Ok(Expr::new(initial_start, last_end, node))
+    })
 }
 
 #[cfg(test)]