Calls to CFE_SB_Subscribe() are missing return checks

[thnkslprpt]

Checklist

• I reviewed the Contributing Guide.
• I performed a cursory search to see if the bug report is relevant, not redundant, nor in conflict with other tickets.

Describe the bug
Calls to CFE_SB_Subscribe() are missing return checks in the initialization code.

Code snips

to_lab/fsw/src/to_lab_app.c

Lines 184 to 191 in fe6c9fd

	if (status == CFE_SUCCESS)
	{
	CFE_SB_Subscribe(CFE_SB_ValueToMsgId(TO_LAB_CMD_MID), TO_LAB_Global.Cmd_pipe);
	CFE_SB_Subscribe(CFE_SB_ValueToMsgId(TO_LAB_SEND_HK_MID), TO_LAB_Global.Cmd_pipe);
	/* Create TO TLM pipe */
	status = CFE_SB_CreatePipe(&TO_LAB_Global.Tlm_pipe, ToTlmPipeDepth, ToTlmPipeName);

Expected behavior
Check returns for all critical function calls during initialization.

Reporter Info
Avi Weiss   @thnkslprpt