gso: fix buffers trace

When segmenting, new buffers must inherit the original buffer trace
handle.

Type: fix

Change-Id: Ibd1859a501b2862906dfc563b98652cfee5681da
Signed-off-by: Benoît Ganne <bganne@cisco.com>
diff --git a/src/vnet/gso/node.c b/src/vnet/gso/node.c
index 5998a4f..0690161 100644
--- a/src/vnet/gso/node.c
+++ b/src/vnet/gso/node.c
@@ -79,6 +79,7 @@
   nb0->current_data = b0->current_data;
   nb0->total_length_not_including_first_buffer = 0;
   nb0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID | flags;
+  nb0->trace_handle = b0->trace_handle;
   clib_memcpy_fast (&nb0->opaque, &b0->opaque, sizeof (nb0->opaque));
   clib_memcpy_fast (vlib_buffer_get_current (nb0),
 		    vlib_buffer_get_current (b0), length);