Update compiler/rustc_lint/src/let_underscore.rs

diff --git a/compiler/rustc_lint/src/let_underscore.rs b/compiler/rustc_lint/src/let_underscore.rs
index b51c1679f9f3131b7d23b781dd8913a288276d6b..c59f56756c6b716f9d5255bb28e3717038e39365 100644 (file)
--- a/compiler/rustc_lint/src/let_underscore.rs
+++ b/compiler/rustc_lint/src/let_underscore.rs
@@ -11,7 +11,7 @@
     /// scope.
     ///
     /// ### Example
-    /// ```compile_fail
+    /// ```rust,compile_fail
     /// struct SomeStruct;
     /// impl Drop for SomeStruct {
     ///     fn drop(&mut self) {