net/mlx5e: CT: Initialize err to 0 to avoid warning

It is theoretically possible to return bogus uninitialized values from
mlx5_tc_ct_entry_replace_rules, even though in practice this will never
be the case as the flow rule will be part of at least the regular ct
table or the ct nat table, if not both.

But to reduce noise, initialize err to 0.

Fixes: 49d37d05 ("net/mlx5: CT: Separate CT and CT-NAT tuple entries")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20240708080025.1593555-11-tariqt@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>