[NFC][libc++] Rewrites a return statement.

This fixes a clang-tidy diagnostic when building libc++ with RTTI
disabled. This was originally part of #65518.

Author: mordante

libcxx/include/any

@@ -194,9 +194,7 @@ namespace __any_imp
       if (__id && *__id == typeid(_Tp))
           return true;
 #endif
-      if (!__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>())
-          return true;
-      return false;
+      return !__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>();
   }
 
   template <class _Tp>