Fix another typo

Author: sjwang05

clippy_lints/src/manual_option_folding.rs

@@ -24,7 +24,7 @@ declare_clippy_lint! {
     /// Use instead:
     /// ```rust
     /// let opt: Option<i32> = None;
-    /// let res: i32 = foo().unwrap_or(42);
+    /// let res: i32 = opt.unwrap_or(42);
     /// ```
     #[clippy::version = "1.74.0"]
     pub MANUAL_OPTION_FOLDING,