Remove unnecessary dyn Display in favor of str

compiler/rustc_trait_selection/src/error_reporting/infer/region.rs

@@ -967,7 +967,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 format!("...so that the {}", sup_trace.cause.as_requirement_str()),
             );
 
-            err.note_expected_found(&"", sup_expected, &"", sup_found);
+            err.note_expected_found("", sup_expected, "", sup_found);
             return if sub_region.is_error() | sup_region.is_error() {
                 err.delay_as_bug()
             } else {

compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

@@ -2846,9 +2846,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             // Print type mismatch
             let (expected_args, given_args) = self.cmp(expected_ty, given_ty);
             err.note_expected_found(
-                &"a closure with signature",
+                "a closure with signature",
                 expected_args,
-                &"a closure with signature",
+                "a closure with signature",
                 given_args,
             );
         }