CFE_SB_ValidateChecksum implementation does not match description

[skliper]

Describe the bug
CFE_SB_ValidateChecksum claims it returns true if not supported:

cFE/fsw/cfe-core/src/inc/cfe_sb.h

Lines 1314 to 1316 in d217ca3

	** \par Assumptions, External Events, and Notes:
	** - If the underlying implementation of software bus messages does not
	** include a checksum field, then this routine will always return \c true.

but also claims it returns false:

cFE/fsw/cfe-core/src/inc/cfe_sb.h

Lines 1321 to 1323 in d217ca3

	** \return Boolean checksum result
	** \retval true The checksum field in the packet is valid.
	** \retval false The checksum field in the packet is not valid or the message type is wrong.

and then implements a false return:

cFE/fsw/cfe-core/src/sb/cfe_sb_util.c

Lines 398 to 401 in d217ca3

	/* if msg type is telemetry or there is no secondary hdr... */
	if((CCSDS_RD_TYPE(MsgPtr->Hdr) == CCSDS_TLM)||(CCSDS_RD_SHDR(MsgPtr->Hdr) == 0)){
	return false;
	}/* end if */

To Reproduce
Read the code.

Expected behavior
Consistency

Code snips
See above

System observed on:
N/A

Additional context
None

Reporter Info
Jacob Hageman - NASA/GSFC

[skliper]

I'd expect this sort of inconsistency to be uncovered during unit test development.