net/mlx5e: fix double free of encap_header in update funcs

net/mlx5e: fix double free of encap_header in update funcs

Follow up to the previous patch to fix the same issue for
mlx5e_tc_tun_update_header_ipv4{6} when mlx5_packet_reformat_alloc()
fails.

When mlx5_packet_reformat_alloc() fails, the encap_header allocated in
mlx5e_tc_tun_update_header_ipv4{6} will be released within it. However,
e->encap_header is already set to the previously freed encap_header
before mlx5_packet_reformat_alloc(). As a result, the later
mlx5e_encap_put() will free e->encap_header again, causing a double free
issue.

mlx5e_encap_put()
     --> mlx5e_encap_dealloc()
         --> kfree(e->encap_header)

This patch fix it by not setting e->encap_header until
mlx5_packet_reformat_alloc() success.

Fixes: a54e20b4fcae ("net/mlx5e: Add basic TC tunnel set action for SRIOV offloads")
Signed-off-by: Gavin Li <gavinl@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20231114215846.5902-7-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>