Address review comment

Author: estebank

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -417,16 +417,20 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     self.add_object_lifetime_default_note(tcx, err, unsize_ty);
                 }
 
-                for constraint in path {
-                    if let ConstraintCategory::Predicate(pred) = constraint.category
-                        && !pred.is_dummy()
-                    {
-                        err.span_note(
-                            pred,
-                            format!("requirement that the value outlives `{region_name}` introduced here"),
-                        );
-                        break;
-                    }
+                if let Some(pred) = path
+                    .iter()
+                    .filter_map(|constraint| match constraint.category {
+                        ConstraintCategory::Predicate(pred) if !pred.is_dummy() => Some(pred),
+                        _ => None,
+                    })
+                    .next()
+                {
+                    err.span_note(
+                        pred,
+                        format!(
+                            "requirement that the value outlives `{region_name}` introduced here"
+                        ),
+                    );
                 }
 
                 self.add_lifetime_bound_suggestion_to_diagnostic(err, &category, span, region_name);