CF CF_CFDP_MsgOutGet method double checks msg for NULL

[jphickey]

This issue was imported from the GSFC issue tracking system

Imported from: [GSFCCFS-1727] CF CF_CFDP_MsgOutGet method double checks msg for NULL
Originally submitted by: Gibson, Alan S. (GSFC-5870) on Mon Sep 13 09:59:14 2021

Original Description:
The function CF_CFDP_MsgOutGet in cf_cfdp.c checks if(!CF_AppData.engine.out.msg) (line 356) as a top if block; however, it then checks it again as part of the if block
if(!CF_AppData.engine.out.msg&&((CF_AppData.config_table->chan[t->chan_num].sem_name[0]&&                     (OS_CountSemTimedWait(c->sem_id, 0)==OS_SUCCESS))||                     (!CF_AppData.config_table->chan[t->chan_num].sem_name[0])))
(starting on line 365 <- yep not a typo line 356 and 365, funny), but there is nothing in between that could change it.

It would appear that this check in the second if is not required.

[jphickey]

This was cleaned up as part of moving this code to a separate file (cf_cfdp_sbintf.c) as part of #137.