mptcp, btf: Add struct mptcp_sock definition when CONFIG_MPTCP is disabled

The btf_sock_ids array needs struct mptcp_sock BTF ID for the
bpf_skc_to_mptcp_sock helper.

When CONFIG_MPTCP is disabled, the 'struct mptcp_sock' is not
defined and resolve_btfids will complain with:

  [...]
  BTFIDS  vmlinux
  WARN: resolve_btfids: unresolved symbol mptcp_sock
  [...]

Add an empty definition for struct mptcp_sock when CONFIG_MPTCP
is disabled.

Fixes: 3bc253c2e652 ("bpf: Add bpf_skc_to_mptcp_sock_proto")
Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions