Reduce scope of lock to within if statement in CFE_SB_ReleaseMessageBuffer

[skliper]

Is your feature request related to a problem? Please describe.
Locks outside if:

cFE/modules/sb/fsw/src/cfe_sb_api.c

Lines 2129 to 2138 in c8b5e00

	CFE_SB_LockSharedData(__func__, __LINE__);
	if (Status == CFE_SUCCESS)
	{
	/* Clear the ownership app ID and decrement use count (may also free) */
	BufDscPtr->AppId = CFE_ES_APPID_UNDEFINED;
	CFE_SB_DecrBufUseCnt(BufDscPtr);
	}
	CFE_SB_UnlockSharedData(__func__, __LINE__);

Describe the solution you'd like
Move inside

Describe alternatives you've considered
None

Additional context
Code review

Requester Info
Jacob Hageman - NASA/GSFC