rustdoc: clean up search index generator code

Co-Authored-By: Guillaume Gomez <guillaume1.gomez@gmail.com>

Author: notriddle

src/librustdoc/html/render/search_index.rs

@@ -185,11 +185,10 @@ pub(crate) fn build_index<'tcx>(
                         lastpathid,
                         crate_paths,
                     );
-                    if let Some(converted_associated_type) = converted_associated_type {
-                        *associated_type = converted_associated_type;
-                    } else {
+                    let Some(converted_associated_type) = converted_associated_type else {
                         return false;
-                    }
+                    };
+                    *associated_type = converted_associated_type;
                     for constraint in constraints {
                         convert_render_type(
                             constraint,
@@ -508,15 +507,9 @@ pub(crate) fn get_function_type_for_search<'tcx>(
         }
     });
     let (mut inputs, mut output, where_clause) = match *item.kind {
-        clean::FunctionItem(ref f) => {
+        clean::FunctionItem(ref f) | clean::MethodItem(ref f, _) | clean::TyMethodItem(ref f) => {
             get_fn_inputs_and_outputs(f, tcx, impl_or_trait_generics, cache)
         }
-        clean::MethodItem(ref m, _) => {
-            get_fn_inputs_and_outputs(m, tcx, impl_or_trait_generics, cache)
-        }
-        clean::TyMethodItem(ref m) => {
-            get_fn_inputs_and_outputs(m, tcx, impl_or_trait_generics, cache)
-        }
         _ => return None,
     };