rustdoc: clean up retain conditon in link ambiguity handling

Author: lolbinarycat

src/librustdoc/lib.rs

@@ -17,7 +17,6 @@
 #![feature(test)]
 #![feature(type_alias_impl_trait)]
 #![feature(type_ascription)]
-#![feature(iterator_try_reduce)]
 #![recursion_limit = "256"]
 #![warn(rustc::internal)]
 #![allow(clippy::collapsible_if, clippy::collapsible_else_if)]

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -2257,13 +2257,7 @@ fn ambiguity_error(
     // and only if we already found something that looks like a proc macro.
     if is_proc_macro_crate && let Some(macro_id) = possible_proc_macro_id {
         kinds.retain(|res| {
-            if let Res::Def(DefKind::Fn, fn_id) = res
-                && macro_id == *fn_id
-            {
-                false
-            } else {
-                true
-            }
+            !matches!(res, Res::Def(DefKind::Fn, fn_id) if macro_id == *fn_id)
         });
     }