Set freeXLOCAL to NULL after freeing it to prevent double frees

We shouldn't be calling the LocalEndTransports routine twice, but
just make sure if we do, we don't call free twice on the same pointer.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

Xtranslcl.c

@@ -1703,6 +1703,7 @@ TRANS(LocalEndTransports)(void)
 {
     prmsg(3,"LocalEndTransports()\n");
     free(freeXLOCAL);
+    freeXLOCAL = NULL;
 }
 
 #define TYPEBUFSIZE	32