Bug 1244338 - Don't try to clean up |ctx| if null. r=drno

--HG--
extra : transplant_source : %22%1Bw%13e%E3HU%CA%3E%EC%14%9Ce%9CR%B6g%7D%01

media/mtransport/third_party/nICEr/src/ice/ice_ctx.c

@@ -418,7 +418,7 @@ int nr_ice_ctx_create(char *label, UINT4 flags, nr_ice_ctx **ctxp)
 
     _status=0;
   abort:
-    if(_status)
+    if(_status && ctx)
       nr_ice_ctx_destroy_cb(0,0,ctx);
 
     return(_status);