-Added <stddef.h> header to fix implicit declaration warnings
-Added ksft_exit_fail_msg() return value checks for fchdir and chroot

Signed-off-by: Abhinav Jain <jain.abhinav177@gmail.com>
---
 .../filesystems/statmount/statmount_test.c          | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test.c b/tools/testing/selftests/filesystems/statmount/statmount_test.c
index 3eafd7da58e2..47ee57da9942 100644
--- a/tools/testing/selftests/filesystems/statmount/statmount_test.c
+++ b/tools/testing/selftests/filesystems/statmount/statmount_test.c
@@ -124,8 +124,17 @@ static uint32_t old_root_id, old_parent_id;
 
 static void cleanup_namespace(void)
 {
-	fchdir(orig_root);
-	chroot(".");
+	int ret;
+
+	ret = fchdir(orig_root);
+	if (ret == -1)
+		ksft_exit_fail_msg("changing current directory: %s\n",
+				strerror(errno));
+
+	ret = chroot(".");
+	if (ret == -1)
+		ksft_exit_fail_msg("chroot: %s\n", strerror(errno));
+
 	umount2(root_mntpoint, MNT_DETACH);
 	rmdir(root_mntpoint);
 }
-- 
2.25.1