CFE_SB_GetLastSenderID returns pointer to internal data, possible race

[skliper]

Describe the bug
CFE_SB_GetLastSenderID returns pointer to data that could be overwritten at any time

See #605 (comment) for related comments

To Reproduce
Conceptually - app calls CFE_SB_GetLastSenderID, gets pointer, data gets overwritten, app takes action based on overwritten data vs original context

Expected behavior
No race.

Code snips

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

Lines 1651 to 1657 in 60a5f65

	/* Get ptr to buffer descriptor for the last msg received on the given pipe */
	Ptr2BufDescriptor = CFE_SB.PipeTbl[PipeId].CurrentBuff;
	/* Set the receivers pointer to the adr of 'Sender' struct in buf descriptor */
	*Ptr = (CFE_SB_SenderId_t *) &Ptr2BufDescriptor -> Sender;
	CFE_SB_UnlockSharedData(__func__,__LINE__);

System observed on:
N/A

Additional context
#605

Reporter Info
Jacob Hageman

[skliper]

Ping @CDKnightNASA @tngo67 and any other user's of this API (SBN related?)

[astrogeco]

Closed, See #816