Part #17, update code coverage

[chillfig]

Increases code coverage for fm_child_tests.c and fm_cmds_tests.c

Checklist (Please check before submitting)

• [x] I reviewed the Contributing Guide.
• [x] I signed and emailed the appropriate Contributor License agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution A clear and concise description of what the contribution is.

• Part #17

Testing performed

1. lcov --capture --rc lcov_branch_coverage=1 --directory build --output-file coverage_test.info
2. lcov --rc lcov_branch_coverage=1 --add-tracefile coverage_base.info --add-tracefile coverage_test.info --output-file coverage_total.info
3. genhtml coverage_total.info --branch-coverage --output-directory lcov

Expected behavior changes None

System(s) tested on

• OS: Ubuntu 18.04

Additional context None

Contributor Info - All information REQUIRED for consideration of pull request Full name and company/organization/center of all contributors ("Personal" if individual work)

• Note CLA's apply to software contributions.

[astrogeco]

@chillfig looks like the code-format check is failing, probably need some whitespace changes

[astrogeco]

CCB:2022.06.22 APPROVED