style: Clarify code intention

Author: epage

src/cargo/core/resolver/dep_cache.rs

@@ -207,7 +207,6 @@ impl<'a> RegistryQueryer<'a> {
             }
         }
 
-        let first_version = first_version;
         self.version_prefs.sort_summaries(&mut ret, first_version);
 
         let out = Poll::Ready(Rc::new(ret));

src/cargo/util/toml/mod.rs

@@ -507,7 +507,7 @@ fn normalize_toml(
 
         normalized_toml.badges = original_toml.badges.clone();
     } else {
-        for field in original_toml.requires_package() {
+        if let Some(field) = original_toml.requires_package().next() {
             bail!("this virtual manifest specifies a `{field}` section, which is not allowed");
         }
     }