Fix nasa#146, When managing the Filter and Dest file tables, the retu…

[myc-yang]

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• 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
When managing the Filter and Dest file tables, the return value of CFE_TBL_GetAddress() after the tables have already been loaded will be checked. Fixes #146

Testing performed
Updated and ran the unit tests DS_TableManageDestFile_Test_TableInfoUpdatePending() and DS_TableManageFilter_Test_TableInfoUpdatePending() in unit-test/ds_table_tests.c

Expected behavior changes

• If either the dest file and filter tables have already been loaded and there is an update pending but the call to CFE_TBL_GetAddress() fails, an error event message (id = DS_TBL_GET_ADDR_ERR_EID) will be issued.

System(s) tested on

• Hardware: PC
• OS: Ubuntu 18.04
• Versions: [e.g. cFE 6.6, OSAL 4.2, PSP 1.3 for mcp750, any related apps or tools]

Additional context
Add any other context about the contribution here.

Third party code
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Contributor Info - All information REQUIRED for consideration of pull request
Michael Yang, NASA/GSFC

[jphickey]

First of all -- in this case I agree that the return value of CFE_TBL_GetAddress absolutely needs to be checked.

My concern with this approach is that adding this many if/else branches significantly increases the code complexity of these functions. I didn't run the numbers but I suspect this will trigger other analysis warnings about this.

Can we simplify this code by splitting this into some subroutines or something so that we don't have if/else logic this deep in one function?