fix rclc_example: memory leaking in msg.data allocation (backport #386)

[mergify[bot]]

This is an automatic backport of pull request #386 done by Mergify.

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[Zard-C]

https://build.ros2.org/job/Rpr__rclc__ubuntu_jammy_amd64/163/clang-tidy/new/folder.-84953004/ It seems that clang-tidy does not pass the check, due to ‘rcl_timer_init’ is deprecated: Call rcl_timer_init2 instead

[codecov-commenter]

Codecov Report

Merging #387 (605a475) into rolling (14c2c41) will decrease coverage by 0.20%. The diff coverage is 50.00%.

@@             Coverage Diff             @@
##           rolling     #387      +/-   ##
===========================================
- Coverage    69.63%   69.44%   -0.20%     
===========================================
  Files           16       16              
  Lines         2760     2762       +2     
  Branches       766      766              
===========================================
- Hits          1922     1918       -4     
- Misses         452      456       +4     
- Partials       386      388       +2     

Files Changed	Coverage Δ
rclc/src/rclc/timer.c	58.33% <50.00%> (-11.67%)	:arrow_down:

... and 1 file with indirect coverage changes

[JanStaschulat]

I made DCO check pass.