address warning: statement with no effect. (backport #559)

[mergify]

Description

see https://ci.ros2.org/job/ci_linux-aarch64/21795/clang-tidy/folder.-1643903456/source.270fa858-97ec-4b07-9c86-ec11c84b9370/#478

--- stderr: rcutils                                                            
In file included from /root/ros2_ws/colcon_ws/src/ros2/rcutils/src/filesystem.c:42:
/root/ros2_ws/colcon_ws/src/ros2/rcutils/src/filesystem.c: In function ‘rcutils_dir_iter_next’:
/root/ros2_ws/colcon_ws/src/ros2/rcutils/src/filesystem.c:478:67: warning: statement with no effect [-Wunused-value]
  478 |   RCUTILS_CHECK_FOR_NULL_WITH_MSG(iter->state, "iter is invalid", false);
      |                                                                   ^~~~~
/root/ros2_ws/colcon_ws/src/ros2/rcutils/include/rcutils/error_handling.h:215:7: note: in definition of macro ‘RCUTILS_CHECK_FOR_NULL_WITH_MSG’
  215 |       error_statement; \
      |       ^~~~~~~~~~~~~~~
---

Fixes # (issue)

Is this user-facing behavior change?

No

Did you use Generative AI?

No

Additional Information

we need to backport this fix to all downstream branches.

---

This is an automatic backport of pull request #559 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of e04f58b has failed:

On branch mergify/bp/humble/pr-559
Your branch is up to date with 'origin/humble'.

You are currently cherry-picking commit e04f58b.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/filesystem.c

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[fujitatomoya]

Pulls: #563
Gist: https://gist.githubusercontent.com/fujitatomoya/3a4ed77af9d648b71a1a109534bab24f/raw/55419388d11b4be50167f8654abd3067b296efcb/ros2.repos
BUILD args: --packages-above-and-dependencies rctils
TEST args: --packages-above rctils
ROS Distro: humble
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/19226

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[ahcorde]

Pulls: #563
Gist: https://gist.githubusercontent.com/ahcorde/3e03ab7ef2fc41805ad77c084514d873/raw/55419388d11b4be50167f8654abd3067b296efcb/ros2.repos
BUILD args: --packages-above-and-dependencies rcutils
TEST args: --packages-above rcutils
ROS Distro: humble
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/19237

• Linux
• Linux-aarch64
• Linux-rhel
• Windows