[OpenMP][NFC] Minimize memory usage and copying of `OMPTraitInfo`s

See rational here: https://reviews.llvm.org/D71830#1922656

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D76173
diff --git a/clang/lib/AST/AttrImpl.cpp b/clang/lib/AST/AttrImpl.cpp
index 2c76f86..a5ff68c 100644
--- a/clang/lib/AST/AttrImpl.cpp
+++ b/clang/lib/AST/AttrImpl.cpp
@@ -159,7 +159,7 @@
     OS << ")";
   }
   OS << " match(";
-  traitInfos.print(OS, Policy);
+  traitInfos->print(OS, Policy);
   OS << ")";
 }