Use defined return values in load_module in more places.

(closes issue #11096)
Patches:
      pbx_config.c.patch uploaded by moy (license 222)
      pbx_dundi.c.patch uploaded by moy (license 222)
      pbx_gtkconsole.c.patch uploaded by moy (license 222)
      pbx_loopback.c.patch uploaded by moy (license 222)
      pbx_realtime.c.patch uploaded by moy (license 222)
      pbx_spool.c.patch uploaded by moy (license 222)
      app_adsiprog.c.patch uploaded by moy (license 222)
      app_alarmreceiver.c.patch uploaded by moy (license 222)
      app_amd.c.patch uploaded by moy (license 222)
      app_authenticate.c.patch uploaded by moy (license 222)
      app_cdr.c.patch uploaded by moy (license 222)
      app_zapateller.c.patch uploaded by moy (license 222)
      app_zapbarge.c.patch uploaded by moy (license 222)
      app_zapras.c.patch uploaded by moy (license 222)
      app_zapscan.c.patch uploaded by moy (license 222)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@94806 65c4cc65-6c06-0410-ace0-fbb531ad65f3