bpf: Use sk_is_inet() and sk_is_unix() in __cgroup_bpf_run_filter_sock_addr().

bpf: Use sk_is_inet() and sk_is_unix() in __cgroup_bpf_run_filter_sock_addr().

sk->sk_family should be read with READ_ONCE() in
__cgroup_bpf_run_filter_sock_addr() due to IPV6_ADDRFORM.

Also, the comment there is a bit stale since commit 859051dd165e
("bpf: Implement cgroup sockaddr hooks for unix sockets"), and the
kdoc has the same comment.

Let's use sk_is_inet() and sk_is_unix() and remove the comment.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20260203213442.682838-2-kuniyu@google.com