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>
authored by