Fix #2260, Convert CFE_TBL_INFO_TABLE_LOCKED into a negative error code

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to [email protected] and copied [email protected].

Describe the contribution

• Fixes CFE_TBL_INFO_TABLE_LOCKED should be a negative error code #2260 (one of the cases of multiple 'success' return codes identified in Deprecate multiple "success" code responses #483).
  • CFE_TBL_INFO_TABLE_LOCKED in CFE_TBL_UpdateInternal() converted into a negative error return code. Not updating the table is a clear failure, and it should not be represented by a positive return value, giving an impression of success.

Testing performed
GitHub CI actions (incl. Code Coverage Analysis, Functional Test etc.) all passing successfully.

CFE_TBL_Update() (which calls CFE_TBL_UpdateInternal()) tests for (Status < 0) which is now triggered by CFE_TBL_INFO_TABLE_LOCKED as well, and the branch for a non-NULL RegRecPtr was not previously covered. With these changes, that branch is now executed by the existing tests. This results in an increase in coverage of 2 lines and 1 branch:

Prior to the changes:
  lines......: 98.1% (13074 of 13326 lines)
  functions..: 97.0% (1041 of 1073 functions)
  branches...: 97.1% (5870 of 6047 branches)
  
With the changes:
  lines......: 98.1% (13076 of 13326 lines)
  functions..: 97.0% (1041 of 1073 functions)
  branches...: 97.1% (5871 of 6047 branches)

Expected behavior changes
Behavior of the function is the same. Only the return code in the case of trying to update a locked table is changing from positive to negative.

The only use of CFE_TBL_Update() from other apps where the return value is checked (e.g. in HK) use == CFE_SUCCESS, so will not be affected by this change. Other (non-public) users who were checking the return of CFE_TBL_Update() and testing less precisely for return >= 0 (or similar equivalents) will see a change, but it seems unlikely that they would consider a non-update as success anyway.

System(s) tested on
Intel(R) Celeron(R) N4100 CPU @ 1.10GHz x86_64
Debian GNU/Linux 11 (bullseye)
Current main branch of cFS.

Contributor Info
Avi Weiss @thnkslprpt

[thnkslprpt]

Note: will need to update the coverage minimums in code-coverage.yml when this is merged. To what numbers will depend on when this is merged in relation to other PRs that also improve coverage.