Fix #147, Add check for success of CFE_TBL_Load() during Initialization

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• 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

• Fixes Need to check the status of CFE_TBL_Load() call #147
  • Adds check for success of CFE_TBL_Load(), if unsuccessful reports "Error Loading Table..." and returns early with error code returned from CFE_TBL_Load().

Testing performed
Tested using same steps as @jphickey used in raising the issue (Start cFS without the sample app table file present in the /cf directory). Confirmed action of new code as per screenshot below:

Expected behavior changes
Sample App will exit during initialization if return value of CFE_TBL_Load() is not CFE_SUCCESS.

System(s) tested on
Intel(R) Celeron(R) N4100 CPU @ 1.10GHz x86_64
Debian GNU/Linux 11 (bullseye)
cFE v7.0.0-rc4+dev197
Sample App v1.3.0-rc4+dev35

Contributor Info
Avi Weiss @thnkslprpt

[jphickey]

This is probably a good thing, at least to display the status after load.

One could debate about returning the error status though - that will probably cause the app to exit itself, but in a "real" FSW environment the tables are loadable at runtime via command. So in that context a real app might just start but go dormant until a table is loaded. On the flip side, the app can also be restarted via command too.

I do concur that the status of CFE_TBL_Load() should be checked in some way though, it is an important return code.

[thnkslprpt]

One could debate about returning the error status though - that will probably cause the app to exit itself, but in a "real" FSW environment the tables are loadable at runtime via command. So in that context a real app might just start but go dormant until a table is loaded. On the flip side, the app can also be restarted via command too.

Fair point Joe. Is it worth adding a comment above the return status line, something like:
/* The early return with error status below can be commented out/removed if user prefers silent fail and syslog report only */

Or just leave as is?