Small performance improvement when comparing symbols for maybe_misused_cfg

Author: GuillaumeGomez

clippy_lints/src/attrs.rs

@@ -929,7 +929,8 @@ fn check_nested_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) {
 fn check_nested_misused_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) {
     for item in items {
         if let NestedMetaItem::MetaItem(meta) = item {
-            if meta.has_name(sym!(features))
+            if let Some(ident) = meta.ident()
+                && ident.name.as_str() == "features"
                 && let Some(val) = meta.value_str()
             {
                 span_lint_and_sugg(