Remove unnecessary sigils around Symbol::as_str() calls.

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -2340,7 +2340,7 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
                         _ => None,
                     });
                 }
-                suggest_existing(err, &name.as_str()[..], suggs);
+                suggest_existing(err, name.as_str(), suggs);
             }
             [] => {
                 let mut suggs = Vec::new();

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -693,7 +693,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
             intravisit::FnKind::Method(id, _, _) => id.name,
             intravisit::FnKind::Closure => sym::closure,
         };
-        let name: &str = name.as_str();
+        let name = name.as_str();
         let span = span!(Level::DEBUG, "visit_fn", name);
         let _enter = span.enter();
         match fk {