[PATCH net] tools: ynl: avoid dict errors on older Python versions

[Jakub Kicinski <kuba@kernel.org>]

Python 3.9.0 or newer supports combining dicts() with |,
but older versions of Python are still used in the wild
(e.g. on CentOS 8, which goes EoL May 31, 2024).
With Python 3.6.8 we get:

  TypeError: unsupported operand type(s) for |: 'dict' and 'dict'

Use older syntax. Tested with non-legacy families only.

Fixes: f036d936ca57 ("tools: ynl: Add fixed-header support to ynl")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: donald.hunter@gmail.com

This is arguably not a fix, but those trying YNL on 6.4 will likely
appreciate not running into the problem.
---
 tools/net/ynl/lib/ynl.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 39a2296c0003..7c7a54d6841c 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -578,8 +578,9 @@ genl_family_name_to_id = None
                         print('Unexpected message: ' + repr(gm))
                         continue
 
-                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name)
-                           | gm.fixed_header_attrs)
+                rsp_msg = self._decode(gm.raw_attrs, op.attr_set.name)
+                rsp_msg.update(gm.fixed_header_attrs)
+                rsp.append(rsp_msg)
 
         if not rsp:
             return None
-- 
2.40.1