[PATCH v1 net-next] selftests: net: af_unix: Fix a build error of unix_connect.c.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

This patch fixes a build error reported in the link. [0]

  unix_connect.c: In function ‘unix_connect_test’:
  unix_connect.c:115:55: error: expected identifier before ‘(’ token
   #define offsetof(type, member) ((size_t)&((type *)0)->(member))
                                                       ^
  unix_connect.c:128:12: note: in expansion of macro ‘offsetof’
    addrlen = offsetof(struct sockaddr_un, sun_path) + variant->len;
              ^~~~~~~~

The checkpatch.pl will complain about this change, but the root cause of
the build failure is that I fixed this in the v2 -> v3 change. [1]

  CHECK: Macro argument 'member' may be better as '(member)' to avoid precedence issues
  #33: FILE: tools/testing/selftests/net/af_unix/unix_connect.c:115:
  +#define offsetof(type, member) ((size_t)&((type *)0)->member)

[0]: https://lore.kernel.org/linux-mm/202207182205.FrkMeDZT-lkp@intel.com/
[1]: https://lore.kernel.org/netdev/20220702154818.66761-1-kuniyu@amazon.com/

Fixes: e95ab1d85289 ("selftests: net: af_unix: Test connect() with different netns.")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 tools/testing/selftests/net/af_unix/unix_connect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/af_unix/unix_connect.c b/tools/testing/selftests/net/af_unix/unix_connect.c
index 157e44ef7f37..5b231d8c4683 100644
--- a/tools/testing/selftests/net/af_unix/unix_connect.c
+++ b/tools/testing/selftests/net/af_unix/unix_connect.c
@@ -112,7 +112,7 @@ FIXTURE_TEARDOWN(unix_connect)
 		remove("test");
 }
 
-#define offsetof(type, member) ((size_t)&((type *)0)->(member))
+#define offsetof(type, member) ((size_t)&((type *)0)->member)
 
 TEST_F(unix_connect, test)
 {
-- 
2.30.2