[PATCH] selftests/filesystems/mount-notify: fix unused unused result warning

[Chen Linxuan]

When running `make kselftest`, the following compilation warning was 
encountered:

mount-notify_test.c: In function ‘fanotify_rmdir’:
mount-notify_test.c:490:17: warning: ignoring return value of ‘chdir’ declared 
with attribute ‘warn_unused_result’ [-Wunused-result]
  490 |                 chdir("/");
      |                 ^~~~~~~~~~

Signed-off-by: Chen Linxuan <chenlinx...@uniontech.com>
---
Changes in v3:
- Apply changes suggested by Muhammad Usama Anjum
- Link to v2: 
https://lore.kernel.org/all/20250620035125.2938774-2-chenlinx...@uniontech.com/
Changes in v2:
- Apply changes suggested by Shuah Khan
- Link to v1: 
https://lore.kernel.org/all/20250610020758.2798787-2-chenlinx...@uniontech.com/
---
 .../filesystems/mount-notify/mount-notify_test.c       | 10 +++++-----
 .../filesystems/mount-notify/mount-notify_test_ns.c    | 10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git 
a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c 
b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
index 5a3b0ace1a88c..30ed5e00800ba 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
@@ -458,12 +458,12 @@ TEST_F(fanotify, rmdir)
        ASSERT_GE(ret, 0);
 
        if (ret == 0) {
-               chdir("/");
-               unshare(CLONE_NEWNS);
-               mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
-               umount2("/a", MNT_DETACH);
+               ASSERT_EQ(chdir("/"), 0);
+               ASSERT_EQ(unshare(CLONE_NEWNS), 0);
+               ASSERT_EQ(mount("", "/", NULL, MS_REC | MS_PRIVATE, NULL), 0);
+               ASSERT_EQ(umount2("/a", MNT_DETACH), 0);
                // This triggers a detach in the other namespace
-               rmdir("/a");
+               ASSERT_EQ(rmdir("/a"), 0);
                exit(0);
        }
        wait(NULL);
diff --git 
a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c 
b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
index d91946e69591a..11a2cfeb1eb94 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
@@ -486,12 +486,12 @@ TEST_F(fanotify, rmdir)
        ASSERT_GE(ret, 0);
 
        if (ret == 0) {
-               chdir("/");
-               unshare(CLONE_NEWNS);
-               mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
-               umount2("/a", MNT_DETACH);
+               ASSERT_EQ(chdir("/"), 0);
+               ASSERT_EQ(unshare(CLONE_NEWNS), 0);
+               ASSERT_EQ(mount("", "/", NULL, MS_REC | MS_PRIVATE, NULL), 0);
+               ASSERT_EQ(umount2("/a", MNT_DETACH), 0);
                // This triggers a detach in the other namespace
-               rmdir("/a");
+               ASSERT_EQ(rmdir("/a"), 0);
                exit(0);
        }
        wait(NULL);
-- 
2.43.0