bpf, netns: Fix build without CONFIG_INET

When CONFIG_NET is set but CONFIG_INET isn't, build fails with:

  ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_unneed':
  kernel/bpf/net_namespace.c:32: undefined reference to `bpf_sk_lookup_enabled'
  ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_need':
  kernel/bpf/net_namespace.c:43: undefined reference to `bpf_sk_lookup_enabled'

This is because without CONFIG_INET bpf_sk_lookup_enabled symbol is not
available. Wrap references to bpf_sk_lookup_enabled with preprocessor
conditionals.

Fixes: 1559b4aa1db4 ("inet: Run SK_LOOKUP BPF program on socket lookup")
Reported-by: Randy Dunlap <[email protected]>
Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: Jakub Sitnicki <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Randy Dunlap <[email protected]> # build-tested
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions