NAT64: Fix port byte order in nat64_free_out_addr_and_port

Change-Id: Idc050e469a5b697ca5587ddd4e87ac2d48d15658
Signed-off-by: Faicker Mo <faicker.mo@ucloud.cn>
diff --git a/src/plugins/nat/nat64.c b/src/plugins/nat/nat64.c
index 9c73004..748205a 100644
--- a/src/plugins/nat/nat64.c
+++ b/src/plugins/nat/nat64.c
@@ -599,7 +599,7 @@
         case SNAT_PROTOCOL_##N: \
           ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
                   port_host_byte_order) == 1); \
-          clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, port, 0); \
+          clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, port_host_byte_order, 0); \
           a->busy_##n##_ports--; \
           a->busy_##n##_ports_per_thread[thread_index]--; \
           break;