selftest: af_unix: Create its own .gitignore.

Somehow AF_UNIX tests have reused ../.gitignore,
but now NIPA warns about it.

Let's create .gitignore under af_unix/.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20251124212805.486235-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/.gitignore

@@ -4,7 +4,6 @@ bind_timewait
 bind_wildcard
 busy_poller
 cmsg_sender
-diag_uid
 epoll_busy_poll
 fin_ack_lat
 hwtstamp_config
@@ -17,7 +16,6 @@ ipv6_flowlabel
 ipv6_flowlabel_mgr
 ipv6_fragmentation
 log.txt
-msg_oob
 msg_zerocopy
 netlink-dumps
 nettest
@@ -34,9 +32,6 @@ reuseport_bpf_numa
 reuseport_dualstack
 rxtimestamp
 sctp_hello
-scm_inq
-scm_pidfd
-scm_rights
 sk_bind_sendto_listen
 sk_connect_zero_addr
 sk_so_peek_off
@@ -44,7 +39,6 @@ skf_net_off
 socket
 so_incoming_cpu
 so_netns_cookie
-so_peek_off
 so_txtime
 so_rcv_listener
 stress_reuseport_listen
@@ -63,5 +57,3 @@ txtimestamp
 udpgso
 udpgso_bench_rx
 udpgso_bench_tx
-unix_connect
-unix_connreset

tools/testing/selftests/net/af_unix/.gitignore

@@ -0,0 +1,8 @@
+diag_uid
+msg_oob
+scm_inq
+scm_pidfd
+scm_rights
+so_peek_off
+unix_connect
+unix_connreset