selftest: af_unix: Remove test_unix_oob.c.

test_unix_oob.c does not fully cover AF_UNIX's MSG_OOB functionality,
thus there are discrepancies between TCP behaviour.

Also, the test uses fork() to create message producer, and it's not
easy to understand and add more test cases.

Let's remove test_unix_oob.c and rewrite a new test.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: q2ven

tools/testing/selftests/net/.gitignore

@@ -43,7 +43,6 @@ tap
 tcp_fastopen_backup_key
 tcp_inq
 tcp_mmap
-test_unix_oob
 timestamping
 tls
 toeplitz

tools/testing/selftests/net/af_unix/Makefile

@@ -1,4 +1,4 @@
 CFLAGS += $(KHDR_INCLUDES)
-TEST_GEN_PROGS := diag_uid test_unix_oob unix_connect scm_pidfd scm_rights
+TEST_GEN_PROGS := diag_uid scm_pidfd scm_rights unix_connect
 
 include ../../lib.mk