fix doc

Author: fee1-dead

compiler/rustc_middle/src/mir/syntax.rs

@@ -522,7 +522,7 @@ pub enum CallSource {
     /// This was from comparison generated by a match, used by const-eval for better errors
     /// when the comparison cannot be done in compile time.
     ///
-    /// See https://github.com/rust-lang/rust/issues/90237.
+    /// (see <https://github.com/rust-lang/rust/issues/90237>)
     MatchCmp,
     /// Other types of desugaring that did not come from the HIR, but we don't care about
     /// for diagnostics (yet).