[PATCH] selftests/filesystems: Use return value of the function 'chdir()'

[Alessandro Zanni <alessandro.zanni87@gmail.com>]

Fix to use the return value of the function 'chdir("/")' and check if the
return is either 0 (ok) or 1 (not ok, so the test stops).

The patch fies the solves the following errors:
mount-notify_test.c:468:17: warning: ignoring return value of ‘chdir’
declared with attribute ‘warn_unused_result’ [-Wunused-result]
  468 |                 chdir("/");

mount-notify_test_ns.c:489:17: warning: ignoring return value of
‘chdir’ declared with attribute ‘warn_unused_result’ [-Wunused-
result]
  489 |                 chdir("/");

To reproduce the issue, use the command:
make kselftest TARGET=filesystems/statmount

Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 .../selftests/filesystems/mount-notify/mount-notify_test.c      | 2 +-
 .../selftests/filesystems/mount-notify/mount-notify_test_ns.c   | 2 +-
 2 files changed, 2 insertions(+), 2 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 5a3b0ace1a88..a7f899599d52 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
@@ -458,7 +458,7 @@ TEST_F(fanotify, rmdir)
 	ASSERT_GE(ret, 0);
 
 	if (ret == 0) {
-		chdir("/");
+		ASSERT_EQ(0, chdir("/"));
 		unshare(CLONE_NEWNS);
 		mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
 		umount2("/a", MNT_DETACH);
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 d91946e69591..dc9eb3087a1a 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
@@ -486,7 +486,7 @@ TEST_F(fanotify, rmdir)
 	ASSERT_GE(ret, 0);
 
 	if (ret == 0) {
-		chdir("/");
+		ASSERT_EQ(0, chdir("/"));
 		unshare(CLONE_NEWNS);
 		mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
 		umount2("/a", MNT_DETACH);
-- 
2.43.0