5218 posix definition of NULL
correct unistd.h and iso/stddef_iso.h
update gate source affected

@@ -85,11 +85,11 @@
         uintptr_t       baseaddr;
         uintptr_t       dentry_addr;
         Elf3264_Dyn     *dynam_tab = NULL;
         long            dynam_tab_size;
 
-        *entaddr_p = NULL;
+        *entaddr_p = (uintptr_t)NULL;
 
         prbstat = prb_mainobj_get(hndl->proc_p, &objfd, &baseaddr);
         if (prbstat)
                 return (_tnfctl_map_to_errcode(prbstat));