apply review suggestions

Author: WaffleLapkin

src/librustdoc/html/render/print_item.rs

@@ -797,7 +797,7 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
         if let Some(list) = must_implement_one_of_functions.as_deref() {
             write!(
                 w,
-                "<div class=\"stab must_implement\">At least one of `{}` methods is required.</div>",
+                "<div class=\"stab must_implement\">At least one of the `{}` methods is required.</div>",
                 list.iter().join("`, `")
             );
         }

src/test/rustdoc/must_implement_one_of.rs

@@ -3,7 +3,7 @@
 
 #[rustc_must_implement_one_of(a, b)]
 // @matches c/trait.Trait.html '//*[@class="stab must_implement"]' \
-//      'At least one of `a`, `b` methods is required.$'
+//      'At least one of the `a`, `b` methods is required.$'
 pub trait Trait {
     fn a() {}
     fn b() {}