Fix nasa#497, checked return value for CFE_SB_DeletePipe() in CF_CFDP…

[myc-yang]

Checklist (Please check before submitting)

• 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
In fsw/src/cf_cfdp.c in the function CF_CFDP_DisableEngine(), the return value of CFE_SB_DeletePipe() is ignored. Issue is captured in #497

Testing performed
I updated and ran the unit tests function Test_CF_CFDP_DisableEngine() in unit-test/cf_cfdp_tests.c,

Expected behavior changes

• API Change: None
• Behavior Change: If CFE_SB_DeletePipe() returns less than CFE_SUCCESS, then an error event message will be outputted

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
If included, identify any third party code and provide text file of license

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

[chillfig]

Looks good. Confirmed build and unit test locally.

[myc-yang]

Looks good. Confirmed build and unit test locally.

I ran both and they passed.